APPALACHIAN TRAIL CONFERENCE
Backcountry
Sanitation
Manual
Science knows now
that the most fertile and
effective manure is the
human manure. Do you
know what these piles of
manure are, those carts
of mud caried off at night
from the streets, the frighful
barrels of the nightman,
and the fetid streams of
subterranean mud which
the pavement conceals
from you? All of this is a
flowering, it is green grass,
it is the mint and thyme
and sage, it is game, it is
cattle, it is the satisfied
lowing of heavy kine,
it is the perfumed hay,
it is gilded wheat, it is
bread on your table, it is
warm blood in your veins.
—Victor Hugo,
Les Miserables
Contents
Preface .............................................................................................................................................................. 5
What This Manual is About ................................................................................................................... 5
Never Apologize, Just Explain ............................................................................................................... 7
Acknowledgments ........................................................................................................................................... 9
Part 1—Background of Sanitation Management ......................................................................................... 13
1—A Brief History of Northeastern Backcountry Use and Backcountry Sanitation Management ....... 15
2—The Importance of Backcountry Sanitation Management .............................................................. 17
3—The Decomposition and Composting Process .............................................................................. 22
4—Health and Safety Issues ............................................................................................................... 29
Part 2 — Regulatory and Aesthetic Issues .................................................................................................. 35
5—Integrating Backcountry Sanitation and Local Management Planning .......................................... 36
6—Introduction to the Regulatory Process ......................................................................................... 37
7—The Aesthetics of Backcountry Sanitation Systems ...................................................................... 42
Part 3—Descriptions of Systems .................................................................................................................. 45
8—The Moldering Privy ....................................................................................................................... 46
9—Batch-Bin Composting ................................................................................................................... 63
10—Liquid Separation in Composting Systems .................................................................................. 90
Part 4 — Installations ..................................................................................................................................... 97
11—Case Studies ............................................................................................................................... 98
11.1 Moldering Privy on the A.T. at Little Rock Pond, Vermont ............................................. 98
11.2 Moldering Privy on the A.T. in Massachusetts ............................................................... 99
11.3 Appalachian Mountain Club Clivus Multrum Composting Toilet .................................. 101
11.4 Randolph Mountain Club Bio-Sun Composting Toilet .................................................. 102
11.5 At Home with the Clivus Multrum Composting Toilet ................................................... 108
11.6 Airlift Haul-Out Systems .............................................................................................. 112
11.7 Flush Toilets with Leach Field at High Mountain Huts ................................................. 112
11.8 Prototype Wood-Fired Compost Incinerator ................................................................ 115
12—The Decision Making Process ................................................................................................... 117
13—Gray Water Management in the Backcountry ............................................................................ 128
Contents, continued
Appendices ................................................................................................................................................... 133
A—Glossary of Terms ....................................................................................................................... 134
B—Troubleshooting and General Composting Tips .......................................................................... 137
C—About the Organizations behind this Manual .............................................................................. 145
D—Contact List ................................................................................................................................. 149
E—Bibliography ................................................................................................................................ 159
F—Examples of Stewardship Signs .................................................................................................. 162
G—Sources of Materials for a Batch-Bin System ............................................................................. 172
H—Lightweight Outhouse Plans ....................................................................................................... 174
I—Plans for a Double-Chambered Moldering Privy .......................................................................... 181
J—Plans for a Drying Rack ............................................................................................................... 186
K—Diagram of a Washpit .................................................................................................................. 188
L—Backcountry Sanitation: A Review of Literature and Related Information ................................... 189
M—The Application of a Solar Hot Box to Pasteurize Toilet Compost in Yosemite National Park .... 198
N—Examples of Regulatory Correspondence .................................................................................. 202
O—Article from ATC Newsletter, The Register ................................................................................. 207
P—Owner-Built Continuous Composters .......................................................................................... 211
Q—Plans for a Wooden Packboard .................................................................................................. 213
PREFACE—5
Preface
What This Manual is About
Pete Ketcham, Field Supervisor, Green Mountain Club
The ATC Backcountry Sanitation Manual addresses the management of human
waste in the backcountry. Proper management of human waste protects hikers, the
environment and trail maintainers.
Resolving problems of backcountry sanitation is a continuous challenge for Trail
clubs and land managers. This manual was created in the belief that all remote
recreation areas will benefit from an expanded discussion of backcountry sanitation. The Appalachian Trail Conference (ATC) hopes it will offer a step up for
those who operate composting systems, as well as for those Appalachian Trail (A.T.)
clubs and land managers who have reached a crossroads in backcountry sanitation
decisions.
This manual introduces a new, simpler and often safer method of composting human waste in the backcountry—the moldering privy. It is a design that saves money
and—even more importantly—labor. Whether volunteer or paid, labor has always
been in short supply on the A.T. The moldering privy is suitable for the majority of
sites that need better waste management than pit privies or catholes, and it is cheaper
and easier to implement than other alternatives.
The approaches recommended here are distilled from the experiences of several
hundred people operating composting toilets and other systems that have successfully resolved human waste problems at backcountry sites along the A.T. Primary
emphasis has been placed on composting systems, because they have been the most
successful in the majority of backcountry situations. However, other systems receive
some attention, especially to provide comparisons with composting systems.
The Green Mountain Club and the Appalachian Mountain Club began using
composting systems in the late 1970s, and their systems have undergone continual
evolution and improvement. Several other A.T. clubs and land managers have used
different composting systems with varying success. The most successful systems are
presented in this manual.
See: Section 8, “The Moldering
Privy” in Part 3—Descriptions of
Systems.
6—APPALACHIAN TRAIL CONFERENCE —BACKCOUNTRY SANITATION MANUAL
If you read this manual through, you will discover a lot of repetition. This is intentional, because the manual is being posted on the Web, where readers may download only the chapters that interest them. Therefore, each chapter must be selfcontained, with as much relevant information as possible. Inevitably, this leads to
repetition, although we have tried to minimize it by the use of cross-references to
other chapters where appropriate.
The first four sections provide background for sanitation management. Section 1
covers the history of sanitation on the A.T;Section 2 explains why managing sanitation issues is important; Section 3 outlines the science of composting; and Section 4 discusses the health and safety issues associated with composting. Much of
the information on the science of composting and health and safety issues in sections 3 and 4 was written by Pete Rentz, a Trail volunteer who is also a medical
doctor.
See Appendix D for contact information for the ATC regional field offices.
Sections 5 and 6 cover the regulatory and permitting process, including compliance
with ATC policy and local management plans. This is as important as health and
safety considerations. Local and state sanitation codes and permit requirements do
apply to almost all new sanitation systems and old systems in trouble. Even though
many are written for municipal or residential waste water discharges, sanitation
officials apply them to backcountry situations. It is extremely important that you
check with your regional ATC field office, local A.T. club officers, local land managing agency, and relevant local and state officials to learn how these regulations
are interpreted in the backcountry in your region.
Section 7 addresses the aesthetics of sanitation systems in the backcountry. The
chapter is short, but the issue is vital, in view of the fact that hiking the Trail is, as
much as anything, an aesthetic or even spiritual experience. An unattractive or
obtrusive toilet facility can ruin the feeling of an otherwise pleasant overnight site.
Sections 8 through 10 form the bulk of the text. Section 8 focuses on the mouldering
privy system, Section 9 and 10 describebatch-bin systems in use on or near the A.T.
Topics include collecting, storing, and composting human waste; sanitary procedures; spring and fall operations; and record keeping. Section 11 presents case studies of individual installations. Section 12 guides the process of deciding which system best matches your needs and resources. Section 13 covers management of gray
water (wash water) and food waste.
This manual is not an installation or operation manual for the systems described.
Each system, especially each commercially produced system, has its own manual for
installing and operating it correctly. This manual reviews each system to help
maintainers decide which is best for them. The Appendix tells how to get more
information on that system.
This brief manual does not cover some backcountry waste problems, such as illegal
garbage dumping and managing pack stock and pet wastes. In addition, it does not
cover some methods of handling human waste in the backcountry that have been
used in other parts of the country, such as vault toilets, incinerating toilets and
chemical toilets. Finally, some remote recreation areas can still rely on pit toilets or
catholes. The capabilities of each backcountry site, the impacts imposed by visitors,
and the capabilities of the managing entity must be carefully evaluated. Only then
can a solution tailored to a specific site be developed.
As composting systems and techniques improve, so will this manual, which is why
ATC chose to publish it on the Internet. As readers experiment with different systems, new information and techniques will develop. ATC plans to add to this manual
as each field season produces new information, and to revise it periodically.
PREFACE—7
Much of the information and experience with composting systems has been developed on the Appalachian Trail in the Northeast, but I have tried to make this manual
useful to all A.T. clubs. In April 2000 I traveled to several sites along the A.T., from
Tennessee to Pennsylvania, to meet with regional ATC staff and volunteers. I saw
composting efforts of other clubs and agency partners in operation in the field, and
I learned something of the strengths and challenges of various A.T. clubs. If your
questions are not addressed or your knowledge is omitted, I hope to hear from you so
I can improve future revisions.
Never Apologize, Just Explain
Dick Andrews, Volunteer, Green Mountain Club
Trail maintainers should resist any suggestion that backcountry waste disposal systems are somehow substandard, but tolerable because they are in remote locations.
If this attitude is accepted, it will diminish the Trail’s prospects for continuing as a
practical and enjoyable entity for future generations of hikers, since that will make
the Trail dependent on continued tolerance of what is imagined to be substandard.
Maintainers who do a conscientious job of managing human waste need not apologize for the results of their efforts.
No practical way of disposing of human waste in the backcountry is perfect, if perfection is defined as zero chance of pollution or dispersal of pathogens. However,
when applied appropriately, all of the systems covered in this manual are adequate,
even when compared to household-sewage systems in rural and suburban areas.
By way of comparison, a septic system serving flush toilets, which is commonly considered the “gold standard” of sewage treatment away from central sewage treatment plants, often leaves a lot to be desired. A septic tank does not actually treat
sewage. It liquefies some solids, and separates the remaining solids from water. But,
the water leaving a septic tank and entering a leach field is as contaminated with
pathogens as the sewage going in. Treatment, if it takes place at all, occurs in the
biologically active soil of the leach field, where the septic tank effluent is supposed
to be exposed to air and organisms that prey upon and compete with pathogens.
Dissolved solids are supposed to be taken up as nutrients by plant roots.
However, in actual septic systems, conditions often prevent proper treatment; inadequately treated sewage percolates down to the ground water or out to the surface.
Many leach fields are too cold in winter for biological treatment, and dormant plants
take up no nutrients in winter. Some leach fields are too deep for plants to reach,
even in summer. Waterlogged soil, which prevents aerobic treatment, is common,
either from weather-related flooding or from large inflows of water from extravagant
use of toilets, showers, washing machines and dishwashers. In private conversation,
sanitary engineers estimate that more than half of all septic systems fail to work
properly at least part of the time, even if the septic tanks are pumped when they
should be and soils in the leach field have not become clogged.
8—APPALACHIAN TRAIL CONFERENCE —BACKCOUNTRY SANITATION MANUAL
Few people worry about these shortcomings, probably because the malfunctions are
out of sight. Only in locations like Cape Cod, where large numbers of inadequate
septic systems threaten an important aquifer, is notice taken of the problem.
It is unreasonable to insist on perfection in the backcountry when it is not required
anywhere else. Many systems treating human waste in the backcountry are actually
more effective than rural and suburban systems people live with every day, partly
because human waste is not mixed with such a huge volume of water in the backcountry. We should strive to improve backcountry sanitation even further, but we
can be proud of the progress already made.
ACKNOWLEDGMENTS—9
Acknowledgments
Development of the sanitation systems described in this manual owes much to the
work of hundreds of individuals over many years.
The initial design and testing of the batch-bin composting system was done by the
Backcountry Research Program of the Northeastern Forest Experiment Station in
Durham, N.H., under the leadership of Ray Leonard in the mid-1970s. The system
has been further developed and refined by the Appalachian Mountain Club (AMC)
and the Green Mountain Club (GMC) since then.
The moldering privy is the design of Appalachian Trail Conference (ATC) and
Green Mountain Club Volunteer Dick Andrews. Dick developed the idea of using
red worms in a simplified composting toilet after he successfully used them in his
Clivus Multrum at home. The first moldering privy was installed under Dick’s supervision at Little Rock Pond Shelter on the Appalachian Trail in southern Vermont in 1996. Thanks also go to Scott Christiansen, Gilbert Patnoe, and Cheryl
Vreeland of the Green Mountain Club’s Laraway Section and Leo Leach and Jeff
Bostwick of the Burlington Section for their help and assistance in the additional
development and testing of the moldering privy, and in the moldering privy description in this manual.
This manual reflects changes and innovations along the Appalachian Trail since
the last edition of GMC’s Manual For Bin Composting was published in 1995.
Special credit is due to former Green Mountain Club Field Supervisors Ben Davis
and Paul Neubauer, without whom the previous editions of the Manual for Bin
Composting would not have happened. Much of the development of the GMC’s
composting toilet installations was due to Ben and Paul, and their interest in keeping the GMC at the forefront of backcountry sanitation technology. Largely because of the foundation their work provides, the GMC and ATC dare to hope that
Trail volunteers and land managers will find the ATC Backcountry Sanitation Manual
the best guide currently available.
I must extend special thanks to David Del Porto and Carol Steinfeld of the Center
for Ecological Pollution Prevention (CEPP) of Concord, Mass. Their book, The
See: GMC Manual For Bin Composting
10—APPALACHIAN TRAIL CONFERENCE —BACKCOUNTRY SANITATION MANUAL
See: Appendix D, “State-by-State
Regulatory Contact list.”
Composting Toilet System Book , is at the forefront of information on composting
human waste, including much that is useful in the backcountry. Many other references were dated, so the publication of their book in 1999 was very timely. Many
illustrations, components of several chapters, and the State-by-State Regulatory
Contact list in the Appendix come from The Composting Toilet System Book. I can’t
recommend this book highly enough to complement the ATC Backcountry Sanitation Manual.
See: The Humanure Handbook:
A Guide To Composting Human Manure, in Appendix E, “Bibliography”
I’d like to thank Joseph Jenkins, author of The Humanure Handbook: A Guide to
Composting Human Manure. The book and e-mail correspondence with the author,
who has twenty-four years of experience composting human waste, significantly
enhanced the ATC Backcountry Sanitation Manual. The Humanure Handbook should
be on the bookshelf of anyone maintaining backcountry campsites and facilities.
See: The Composting Toilet System
Book (see Appendix E, “Bibliography” and Appendix C, “About the
Organizations Behind this Manual.)
This manual could not have been produced without the volunteer authors who
wrote much of the material. I’d like to thank authors Dr. Peter Rentz M.D. of the
AMC Massachusetts A.T. Committee; AMC Shelters Program Supervisor Hawk
Metheny; AMC Huts Manager Chris Thayer; Paul Neubauer, a former GMC field
supervisor U.S. Forest Service ranger, and Randolph Mountain Club (RMC) caretaker; former GMC and RMC caretaker Paul Lachapelle; RMC Trails Chairman
Doug Mayer; RMC Field Supervisor Anne Tommasso; ATC New England Regional
Representative J.T. Horn; ,ATC New England Associate Regional Representative
Jody Bickel; Pete Irvine, U.S. Forest Service liaison to the Appalachian Trail Park
Office in Harpers Ferry, W.Va.; and GMC and ATC volunteer Dick Andrews.
At the Green Mountain Club in Vermont, I’d like to thank Trail Management Committee Chair Peter Richardson, Executive Director Ben Rose, former Director of
Field Programs Lars Botzojorns, and Director of Field Programs Dave Hardy for their
support in the creation of this manual.
At the Appalachian Mountain Club’s Pinkham Notch Visitor Center I’d like to
thank Director of Outdoor Program Centers Paul Cunha and Construction Crew
Director Tom Bindas for their technical information on sanitation systems at the
AMC huts and shelters in the White Mountains in New Hampshire. I’d also like to
thank David Boone of the AMC’s Connecticut Trail Committee for his assistance
with information on the regulatory process that governs the installation of composting
toilets on the A.T. in Connecticut. And I’d like to thank Steve Clark at the Maine
Appalachian Trail Club for his input and knowledge as the club’s designated “Privy
Czar.”
At the Blue Mountain Eagle Climbing Club, I’d like to thank Dave Crosby for
showing me his club’s composting efforts on the Trail in Pennsylvania and for providing me with information used in this manual.
At the Mountain Club of Maryland and the Potomac Appalachian Trail Club my
thanks go to Ted Sanderson, developer of the Pennsylvania composter, and Paul
Ives for showing me their systems in Pennsylvania.
At the U.S. Forest Service I’d like to thank Tim Eling at the Mt. Rogers National
Recreation Area; Brenda Land at the San Dimas Technology Center; and Jeff Harvey
at the Green Mountain and Finger Lakes National Forest for sharing knowledge
accumulated from the National Forests on backcountry sanitation.
I’d like to thank George Minnigh at the Great Smoky Mountain National Park and
Pam Underhill at the Appalachian Trail Park Office, both of the National Park
Service. Thanks also go to the National Park Service and its challenge cost-share
program for the financial support that made this project possible.
ACKNOWLEDGMENTS—11
Thanks to Bill Wall and Ben Canonica of Clivus New England for sharing their
knowledge and providing me with materials on the Clivus for the manual. I’d also
like to thank Allen White of Bio Sun Systems Inc., who was also generous with his
time and resources in assisting me with this project.
At the Appalachian Trail Conference, thanks for energetic support—in addition to
writing—go to New England Regional Representative J.T. Horn. I’d also like to
thank ATC Board of Managers New England Vice Chair Brian Fitzgerald and Director of Trail Management Programs Bob Proudman (especially for his continual
encouragement and support in the search for the “sanitation silver bullet”). Also:
Mid-Atlantic Regional Representative Karen Lutz, Mid-Atlantic Associate Representative John Wright, Central and Southwest Virginia Regional Representative
Mike Dawson, Southwest Virginia Associate Representative Teresa Martinez, Tennessee-North Carolina-Georgia Associate Representative Ben Lawhon, Bear’s Den
Hostel Manager Melody Blaney, ATC Editor Robert Rubin, and ATC Management
Information Systems Specialist Hansen Ball.
I’d like to give special thanks to the ATC’s Jody Bickel, associate regional representative for New England. Jody played many key roles in the development of this
manual: volunteer author, associate editor, motivational coach (for helping me deal
with the realities of deadlines), meeting facilitator, contact for the Appalachian
Trail Conference, general source of information, and of course good cheer. Thank
you, Jody, the Sanitation Manual will serve the Appalachian Trail well as a result of
your efforts.
This manual would not have been possible without my editor, Dick Andrews, originator of the mouldering privy system. Dick was the perfect editor for this project—
not only because of his professional skills (he is a free-lance writer and editor by
trade), but because of his twenty-seven-years of experience composting human waste
at his home in southern Vermont. He was an invaluable source of technical information and ideas on this subject. He has also been a long-time ATC and GMC
volunteer, and he was able to apply the volunteer perspective to the manual to
make it as useful as possible to A.T. club volunteers. Thank you, Dick.
Finally, credit for this manual must be given to the many unnamed ATC maintaining club volunteers, ridgerunners, and caretakers who have toiled with few thanks
to make composting on the Appalachian Trail work.
—Peter S. Ketcham, Waterbury Center, Vermont (March 2001)
Part 1
Background for Sanitation Management
1—A Brief History of Northeastern Backcountry Use and Backcountry
Sanitation Management
2—The Importance of Backcountry Sanitation Management
3—The Decomposition and Composting Process
4—Health and Safety Issues
1
A Brief History of Northeastern
Backcountry Use and Backcountry
Sanitation Management
Pete Ketcham, Field Supervisor, Green Mountain Club
In the late 1960s and early 1970s there was a surge in use of backcountry facilities
unlike anything land managers had ever seen. The number of people seeking primitive recreation in the mountains, particularly along the Long Trail in Vermont and
the Appalachian Trail along the East Coast, had increased about ten times since the
1930s. By the mid 1970s, the most popular overnight destinations, such as upperelevation and backcountry pond sites, were receiving as many as seventy overnight
visitors each week during the six-month hiking season. The volume of human waste
increased proportionately from about one gallon per week per site to fourteen gallons per week, or more than three hundred gallons per season at some sites.
Many backcountry facilities in New England were developed between the 1920s
and 1940s on upper mountain slopes to provide scenic views, refuges near summits
or idyllic getaways near the shorelines of mountain ponds. When many of these
facilities were built, the number of visitors was low, averaging five persons per week
per site. At these low levels of use, wastes in pit privies could probably be safely
decomposed and assimilated by soil.
However, the severe limitations of these mountain sites became evident as the number
of visitors increased. Most ridgeline campsites had poor, thin soils that precluded frequent digging of new pit toilets. Most campsites near ponds were located very close to
shorelines, and locating new sites for pit toilets a safe distance from water was difficult
without moving entire campsites. At some sites, helicopters were used to fly waste out,
but many people considered this practice too expensive and intrusive.
Watersheds were being polluted, human health was at risk, and the recreational
experience at managed backcountry facilities was being eroded by unmanageable
amounts of human excrement. These problems prompted the development of alternative waste management systems.
16—APPALACHIAN TRAIL CONFERENCE —BACKCOUNTRY SANITATION MANUAL
In the mid-1970s, the Backcountry Research Program of the USDA Forest Service
Northeastern Forest Experiment Station in Durham, N.H., led by Ray Leonard,
developed the batch-bin composting toilet system as an inexpensive and practical
means of waste disposal for high-use backcountry sites. Since 1977, batch-bin systems have operated continuously at selected sites in the White Mountains of New
Hampshire and the Green Mountains of Vermont, as well as in other areas. Along
other parts of the Appalachian Trail, as use has increased, land managers and maintaining clubs have also begun to study and implement alternative waste management systems at the more fragile and popular campsites.
Backcountry sites in New England were subject to a combination of especially wet
and cold weather, thin and acidic soils, and a flood of backcountry recreationists
from nearby urban areas, since the Green Mountains of Vermont and the White
Mountains of New Hampshire were within a day’s drive of 70 million people. In
retrospect, it is no surprise that the inadequacy of traditional pit toilets became
apparent there sooner than on many other sections of the Appalachian Trail. Consequently, the Green Mountain Club (GMC) and Appalachian Mountain Club
(AMC) have played an active role in the evolution of alternative waste management systems. Between them, the GMC and AMC now manage thirty-eight
composting toilet systems among their more than eighty-six backcountry campsites.
The success of the two clubs’ composting toilet systems rests largely in the hands of
dedicated and knowledgeable field staff and volunteers. Organizational commitment by the GMC, AMC, the Appalachian Trail Conference (ATC), and their
agency partners has ensured the continued success of this effort.
Figure 1.1—Original Clivus Multrum Toilet designed by R.E. Lindstrom of Sweden in
the 1930s. Drawing From Stop the Five Gallon Flush (1980) taken from The Composting
Toilet System Book by David Del Porto and Carol Steinfeld.
2
The Importance of Backcountry
Sanitation Management
Pete Ketcham, Field Supervisor, Green Mountain Club
2.1
Almost all backcountry facilities can benefit from sanitation management. Improper
disposal of wastes at fragile, heavily used remote recreation sites causes pollution of
soil, ground water and surface water, and it degrades the experience of the backcountry user.
BASIC QUESTIONS
Ask the following questions when considering new or improved sanitation facilities:
• Is your organization governed by a Local Management Plan (LMP) or a Forest
or Park Master Plan (Such as National Forests and Parks have)?
• If the answer is yes, does your organization’s LMP specify a role for backcountry
facilities and sanitation systems?
For example, as a member of the Appalachian Trail Conference (ATC), the Green
Mountain Club (GMC) has an LMP to guide its management of the entire 445-mile
Long Trail System in Vermont, which includes the Appalachian Trail. The GMC plan
guides the development of overnight facilities and sanitation facilities in language derived from the ATC’s Local Management Planning Guide. The guide says:
Managing overnight-use areas constitutes an important part of club effort.
Numerous factors must be considered in locating and designing overnight-use
areas, including soils, vegetation, topography, expected visitor use, proximity to
water, distances to roads and other overnight sites, and use of adjoining lands.
Ideally, shelters and campsites should be spaced a modest day’s hike apart, and
they should be designed to contain the social and environmentalimpacts of overnight
visitors within a confined area. Provisions should also be made to for dependable
water supplies andsanitation at each site. Regardless of whether privy or dispersed
disposal area is used to accommodate human waste, the site should be monitored
to ensure that human wastes does not create environmental or health problems.
From Local Management Planning
Guide—Chapter 2 (G) Overnight
Use—Shelters, Campsites, and
Privies, Appalachian Trail Conference, Revised 6/90. See Appendix E.
18—APPALACHIAN TRAIL CONFERENCE —BACKCOUNTRY SANITATION MANUAL
See Section 7, “The Aesthetics of
Backcountry Sanitation Systems,”
and Section 9, “The Decision Making Process.”
All A.T. maintaining clubs are bound by ATC policy to provide for backcountry
sanitation. However, the type of system is left to individual clubs, subject to standard decision-making criteria. Your organization may be guided by a similar policy,
or it may be governed by a state, county, municipality, or land management agency.
See Section 5, “Following Policies
and Regulations.”
Land managers and Trail clubs should carefully consider the following goals when
establishing a designated overnight facility and providing for its sanitation.
• Protection of Water Quality—This is a primary concern. Overnight facilities should
ordinarily be located near a dependable source of drinking water. It is vital not to
compromise the water source by improper disposal of human wastes.
• Prevention of Resource Damage—Central waste systems reached by designated trails
prevent the formation of bootleg trails and damage to vegetation. Sites with no
facilities often have a myriad of bootleg trails to poorly chosen spots (for example, next to the shelter or tent site or near water supplies).
• Protection of Aesthetic Quality—Nothing makes an overnight facility less appealing than untreated sewage on the ground. Even where a toilet area is designated
for disposal of human waste by the hiker in a cathole, waste is likely to surface
unless there is a human presence (for example, a caretaker or ridgerunner). Also,
if a privy smells bad, some hikers will avoid it and deposit their waste on the
ground, often in improper or undesirable locations.
To tailor a solution to a particular site, it is necessary to evaluate the site’s capabilities and the impacts of visitors.
2.2
OVERVIEW OF HUMAN
WASTE IN THE
BACKCOUNTRY
Humanwaste in the backcountry takes four basic forms: Sewage (fecal waste, urine,
pet waste, and nonorganic contaminated trash), food waste, trash and litter, and fire
waste.
Sewage—Sewageis the highest priority because it can spread disease. Traditional
disposal methods such as pit privies and catholes often contaminate water, but they
can be managed to minimize risks.
1. HUMAN FECAL WASTE—Human fecal waste in the backcountry is commonly deposited in the soil in pit-toilets and/or cat-holes, and to a lesser extent on the ground
surface. The following methods for dealing with it are commonly employed:
Pit toilets—The traditional repository. (A pit toilet with no privy shelter is called
a chum toilet.) Because anaerobic waste breakdown in a pit is slow, pathogens
may remain viable for years. The waste in poorly placed privies can leach contaminants into the surrounding area years after use has ceased. However, pits
work well when properly sited and not overused. The level of use must match
local soil characteristics. If you are considering a pit toilet, contact your regional
ATC office for information on siting and installation.
Modified pit toilets—These attempt to avoid anaerobic decomposition in favor of
aerobic decomposition. Modifications include:
• Regularly digging out pits to prolong their life. Wastes are then shallow-buried or composted.
2: IMPORTANCE OF BACKCOUNTRY SANITATION MANAGEMENT—19
• Half-filling newly dug or newly emptied pits with dry leaves and duff. Users
throw in additional organic matter after use. The outhouse is periodically tilted
aside, providing access to mix and aerate the wastes if needed.
Catholes—These are almost always used where established toilet facilities are not
provided. The user digs a small hole, about six inches deep, then covers the waste
with soil.
Catholes are often improperly made, and wastes do not break down quickly, despite the old adage “bury it and it will be gone in two weeks.” Studies by Temple
and others have shown human pathogens remain viable for up to two years in
catholes.
For the cathole method to be effective, users must break up wastes with a stick,
mixing them thoroughly with duff within the cathole before covering with a
mound of leaves and duff. This creates a mini-composting pile in the top layer of
forest soil. This will only work well if the soil that the cathole is dug in is biologically active and diverse with decomposer organisms. At higher elevations, many
of these organisms may be absent.
Catholes are usually unsatisfactory as the sole means of waste disposal at designated facilities. Most users make them improperly, despite educational efforts
either on- or off-site. Some users even deposit wastes on the surface. If you choose
to designate cathole use at certain campsites, consult your regional ATC office
for more information.
Temporary pit latrines—These are typically used by groups, may also create health
hazards in heavily visited overnight sites, due to slow waste breakdown and poor
placement. As with cat-holes, temporary latrines should be shallow, and wastes
should be well-mixed with leaves and duff before being covered with a mound of
leaves and sticks. Many groups mistakenly assume that the deeper the hole, the
better.
Snow holes—These simple holes in the snowpack are a special situation. Although
fecal wastes on snow are subject to solar breakdown and other effects of weathering, they may contaminate spring runoff, especially at sites next to water. Individual knowledge and willingness to make snow holes away from water can reduce adverse impacts. However, provision of usable winter toilet facilities at sites
with high winter use is the best option.
Composting toilets—These are a major improvement over the above methods of
disposing of fecal waste. Site limitations such as shallow soils or high water tables,
coupled with heavy use, have led to the development of batch-bin composting
and moldering privies, as well as more expensive manufactured aerobic composting
toilets.
In a composting toilet, raw wastes are held apart from the surrounding site until
sufficiently decomposed to be spread over the forest floor. However, waste policy
on federal land in the west frequently dictates that even treated waste be transported out of the backcountry.
Dehydration and incineration toilets—These are commercially available. Results
have been mixed. Provision of fuel (usually propane) can be expensive and disruptive, and offensive odors have been reported in some cases.
See studies by Temple, et. al.
(1982), in Appendix E.
20—APPALACHIAN TRAIL CONFERENCE —BACKCOUNTRY SANITATION MANUAL
Removal of wastes—Typically by helicopter, truck or mule train, must be done
where on-site management is not possible. Removal prevents contamination of a
site, but is expensive and can be disruptive.
2. URINE—Urine is usually a hidden waste problem, aside from toilet paper and
yellow snow. The urine of healthy individuals is ordinarily sterile, so the health
hazards associated with urine in the backcountry are comparatively low.
Overnight users tend to urinate in the immediate vicinity of a backcountry facility or campsite. Some use privies and some do not. Urine in anaerobic systems
such as a pit-toilets substantially increases offensive odors. Depending on the
design, urine can be either an asset or a liability in aerobic composting systems,
but odors are much less of a problem in either case.
Day users tend to urinate next to the trail and at privies at overnight sites.
3. DOG WASTE—This is a problem whenever dog owners do not clean up after their
pets. Canine feces should be disposed of using the cathole method. Tracking of dog
feces into water supplies on hikers’ shoes may contribute to the spread of waterborne pathogens such as Giardia lamblia.
See Section 4—“Health and Safety
Issues.”
4. NONORGANIC CONTAMINATED TRASH—Nonbiodegradable items, such as feminine
hygiene products, are thrown into privies by careless visitors. In pit toilets such
trash is generally left in the pit, taking up space and shortening the life of the pit. In
composting systems it is generally retrieved and allowed to weather before being
packed out.
Food waste—Food waste is tossed into the woods, dumped into privies, buried,
burned, rinsed into surface water, or packed out, in the absence of on-site disposal
systems. Ineffective disposal of food waste can offend other hikers, attract nuisance
animals and insects, and pollute water. Trail clubs and land managing agencies should
aggressively teach Leave No Trace outdoor ethics to hikers and backpackers and
thus promote a Carry In-Carry Out Policy for all non-sewage waste, including food.
Disposal by scattering—Can cause excessive nutrient loading to the water table
where shallow soils provide little absorption of nutrients, and attracts nuisance
animals. This practice should be discouraged by land managers.
Disposal in pit toilets—Undesirable due to putrefaction odors, fly attraction, and
animal visitation (particularly bears).
Burying—Can promote decomposition of food wastes when they are actively mixed
with soil in the hole. However, it is a not an ideal solution, because animals may
dig up wastes.
Burning food wastes—Can be effective, but a wood fire must be very hot to completely consume the waste and avoid offensive odors;d most hikers do not have
the skills or tools to accomplish this. In addition, wood is scarce at most campsites, and managers often discourage or prohibit wood fires to avoid scarring trees
or the site.
Rinsing food wastes—Rinsing into surface waters obviously pollutes the water,
and should be prohibited.
Trash and litter—Problems with these are declining with widespread education
about carry-in, carry-out practices.
2: IMPORTANCE OF BACKCOUNTRY SANITATION MANAGEMENT—21
Clean trash: Paper, plastic, foil, cans, and bottles. It is most prevalent in areas
visited by day hikers and non-hikers.
Fishing lines and hooks: These present cleanup and wildlife entanglement problems at heavily used backcountry fishing areas.
Unsorted trash: Food, paper, non-organic trash, etc. It is principally a problem at
trailheads. Hikers often carry out food waste, but then put it in trailhead garbage
cans, attracting animals that scatter garbage. Hikers should be instructed to take
food waste home.
Washing wastes: Food, soap, toothpaste and other hygienic wastes. They contaminate surface and ground water. The installation of washpits, coupled with
Leave No Trace education about low-impact washing practices, has done much
to alert hikers to the growing scarcity of pure drinking water and the need to
keep water sources as clean as possible.
• Dish washing in surface water is a widespread and undesirable practice. The
use of washpits has done much to focus hikers attention away from the water
source as the place to wash. However, washpits that are inappropriately sited,
poorly constructed, or improperly maintained pollute surface and ground water at medium- to high-use overnight sites.
See Section 13, “Gray Water Management in the Backcountry.”
• Hygienic wastes, particularly from hand washing after privy use, are a sanitary
hazard. The waste system should separate privy users from surface water as
much as possible. Sites with the privy and shelter on opposite sides of a watercourse are most prone to water contamination from hand washing.
• Bathing, shaving, and toothbrushing: These pose contamination problems at
all areas with surface water.
Fire wastes—These appear wherever fires are built. Fires built in undesignated places,
such as on the ground, against tree trunks or in unauthorized fireplaces, cause additional damage. Cutting of live trees, excessive wood-gathering, peeling of birch bark,
along with scorched inorganic trash, burn-scarred rocks, and charred wood, are other
adverse impacts associated with backcountry fire use.
2.3
New or improved waste management systems must be chosen after analysis of site
characteristics, available financial and labor resources, and current or projected use.
Continuous educational efforts are essential for effective waste disposal. Backcountry users should have on-site information, from stewardship signs or field personnel,
or information such as guidebooks or pamphlets to instruct them in proper backcountry waste management techniques.
SUMMARY
3
The Decomposition and
Composting Process
Pete Ketcham, Field Supervisor, Green Mountain Club
Pete Rentz M.D., Trails Chairman, Massachusetts A.T. Committee
of the Appalachian Mountain Club—Berkshire Chapter
3.1
INTRODUCTION
Ever since land animals appeared on Earth, feces and urine have been deposited on
the ground. Microorganisms in the soil have evolved to take advantage of these
nutrients. This process may be observed in any well-drained cow pasture where cattle
eat grass, urinate, and defecate. Urine immediately sinks into the soil, and is no
longer evident minutes after it is deposited. Manure stays on the surface for several
days or weeks, eventually decomposing and also disappearing, nourishing the grass
in the process.
When this natural process occurs in a human-controlled environment, we call it
composting. Composting is a method of waste management in which materials of
biological origin are decomposed by common soil microorganisms to a state where
they can be applied to the land with little environmental stress. By using compost as
a soil amendment, soil properties are improved, and nutrients are reclaimed by plants.
Composting requires a container, oxygen, proper moisture, proper temperature range,
aerobic organisms, and time.
Mechanisms of Decomposition—Decomposition can occur either under aerobic conditions (in the presence of oxygen), or under anaerobic conditions (in the absence of
oxygen).
Aerobic decomposition is the primary decomposition process in porous upland soils,
such as the cow pasture described above. The goal of composting is to ensure
aerobic conditions as completely as possible. Rapid breakdown, moderate-to-high
temperatures, lack of odors, and effective pathogen destruction typify well-managed backcountry aerobic-composting operations.
3: DECOMPOSTION AND COMPOSTING PROCESS—23
Anaerobic decomposition in the backcountry is characterized by slow decomposition, comparatively low temperatures, foul odors, and high pathogen survival.
The key to an effective composting process is oxygen, which powers aerobic bacteria and poisons anaerobic bacteria. With oxygen, aerobic bacteria thrive and outcompete anaerobic bacteria, which have slower metabolisms.
3.2
The physical and chemical properties of material being composted, and the temperatures attained, directly affect the rate and extent of microbial activity in the
composting process. The most significant variables affecting the composting of human waste in the backcountry are listed here.
VARIABLES AFFECTING
COMPOSTING
Size of substrate particles—The size of the substrate particles determines the surface area accessible to microbial attack. Smaller particles expose more surface to
bacteria, leading to faster and more complete decomposition. Mixing wastes with
ground bark or a similar bulking agent and breaking up clumps of raw sewage creates
small compost fragments. This results in finished compost that is composed mostly
of fine crumbly particles.
Voids between particles—Voids between particles comprise a significant fraction
of compost volume. These air spaces are the main source of oxygen for the microorganisms which cause decay. Turning of the compost mass can reduce clumping and
compaction, and bring fresh air into the interior of the pile.
Moisture content—The moisture content of compost is critical. Water is the solvent in which organic and inorganic constituents of cells are dissolved, and it serves
as the medium for movement and interaction of various cellular substances.
A moisture content around 60 percent by weight is best for rapid aerobic composting.
Below this, compost becomes too dry for rapid microbial growth, the compost process slows considerably, and pathogen encapsulation (conversion to a temporarily
inactive form protected by a durable coating) is likely. Much above 60 percent,
water begins to collect, and portions of the pile become anaerobic.
Maintaining a suitable moisture content in a system is not difficult, as drainage of
excess liquid tends to make the pile self-regulating.
All of the systems described in this manual can do or can offer drainage of liquids.
Pit toilets and moldering privies discharge their liquid directly into the soil. Moldering privies, however, have the advantage allowing the liquid effluent to pass through
both aerobic portions of the compost bed and the top biological layer of the soil,
providing a high degree of treatment.
Batch-bin systems isolate liquid from the ground and absorb it with a bulking
agent, generally bark mulch. A portion of the liquid is evaporated from the bin
by the heat of the composting process. The remainder gets evaporated in the
drying process.
See Section 9.
The beyond-the-bin system drains liquid from the toilet, and treats it in a filtering
barrel before releasing it into the ground. Any remaining liquid is managed the
same way as in the batch-bin system.
See Section 10.
24—APPALACHIAN TRAIL CONFERENCE —BACKCOUNTRY SANITATION MANUAL
See sections 11 and 12 .
The three commercial continuous composters and the one homemade version described in the manual all have provisions to collect, store, and ultimately treat
and discharge liquid, ideally by running it through a beyond-the-bin filter barrel.
Temperatures—Temperatures attained in composting depend on the configuration,
size and composition of the compost mass, its moisture content, and on its manipulation.
Some water is necessary for aerobic bacteria, but too much moisture inhibits them
and retards composting, which reduces the temperature.
Mesophilic composting, which occurs in moldering toilets, takes place when waste
materials are added slowly. Temperatures may range from 10 degrees C. to 45
degrees C. (50 degrees F. to 112 degrees F.).
Thermophilic composting can follow mesophilic composting in a mass of
uncomposted material large enough to conserve the warmth generated by mesophilic composting. Thermophilic, or heat-loving, bacteria take over, and temperatures may rise well above 50 degrees C. (120 degrees F.), to as much as 75
degrees C. (167 degrees F.). Thermophilic composting is the goal of batch-bin
composting operations.
Every organism has a heat tolerance limit, above which it perishes. Bacteria flourishing in the mesophilic range warm the pile to their own tolerance limits, and are
replaced by thermophilic bacteria. Redworms and many other invertebrates that
thrive in meosphilic composting generally do not tolerate temperatures in the thermophilic range. Eventually the upper limit of the thermophiles is reached, and activity slows and ceases. The temperature falls, and if oxygen and nutrients are again
made available (e.g. by turning the pile), the temperature will rise again. Nutrient
and oxygen availability, ambient temperatures, and pile insulation affect the rate
and extent of heat buildup.
See McKinley, Vestal, and Eralp,
1985, in Appendix E.
It is often assumed that the highest temperatures in the thermophilic range produce
the highest rates of microbial activity. However, the range of greatest bacterial activity is between 35 degrees C. and 45 degrees C. (95 degrees F. to 112 degrees F.).
This range corresponds with adaptation to the soil environment in hot climates. Up
to 55 degrees C. (130 degrees F.) the rate of growth and reproduction is still very
high, but it falls off markedly above 60 degrees C. (140 degrees F.), the limit of the
range of thermophilic bacteria.
Sun and wind have little direct impact on the temperature in a composting chamber, but are worth considering for other reasons.
In most of the backcountry overnight sites along the Appalachian Trail, the sun is
either obscured by mountain fog or by a dense canopy of trees. If selected shading
trees can be removed, it may improve a composting area by keeping it dry and odor
free, and it will help dry compost in a drying rack, but it probably will not enhance
the composting process itself significantly.
At some sites in Pennsylvania, the canopy has been reduced around continuous
composting toilet systems. The sloping tank and vent stack are painted a dark color
to help absorb heat. The Mountain Club of Maryland has reported that solar gain
helps to create draft the vent stack, which helps draw fresh air into the pile and
moisture and odor up the stack.
3: DECOMPOSTION AND COMPOSTING PROCESS—25
Wind can help keep a composting area dry and to dry finished products. It also
enhances the draft in manufactured continuous composting toilets, which can be
desirable, but also can lower the temperature in the composting chamber too much.
The container is critical to reaching thermophilic composting temperatures. It must
hold at least 160 gallons for self-insulating thermophilic composting. It is possible
that an insulated container could be smaller, but this has not been established. Insulation is of no value in mesophilic composting, since heat is produced at a negligible
rate.
Nutrient Elements—Microorganisms utilize a wide array of nutrient elements, most
of which are present in human fecal wastes. Those used in larger amounts are called
macro-nutrients, and include carbon (chemical symbol C), nitrogen (N), phosphorus (P), and potassium (K).
Nutrients are used in fixed proportions by any particular class of organisms, so a
shortage of one nutrient may cause microbial activity to cease before other available
nutrients are consumed. Destruction of pathogens is most effective when nutrients
are approximately balanced so the composting process can utilize most or all of
them. When composting human waste, an optimum balance is created by adding a
bulking agent (e.g. hardwood bark) high in carbon, since human waste contains the
other macro-nutrients in appropriate proportions.
The ratio of carbon to nitrogen—the carbon:nitrogen (or C:N) ratio—is the key to
nutrient balance. Understanding the C:N ratio is critical to the selection of bulking
material, but achieving an effective C:N ratio is not difficult.
If the excess of carbon over nitrogen is too great (high C:N ratio), cell processes
slow down. In that case, nitrogen is limiting. That happens when a bulking material
of very high C:N ratio, such as sawdust, is used exclusively, or when too much of a
bulking agent with a more moderate C:N ratio, such as hardwood bark, is added to
the wastes. Given enough time, nitrogen is recycled and the excess carbon is metabolized to carbon dioxide, but the time required can be too long to be practical for
batch-bin operations.
If the carbon is limiting (low C:N ratio), excess nitrogen is converted to ammonia until
the nutrient balance is restored. That happens when not enough bulking agent (such as
hardwood bark) is added. A low C:N ratio typically encourages anaerobic conditions,
and accounts for the odor of ammonia associated with anaerobic breakdown.
A C:N ratio between 25:1 and 30:1 is optimum for aerobic composting of human
wastes. There is no convenient test to determine whether the C:N ratio is in this
range. Fortunately, however, this is the approximate ratio which occurs when ground
hardwood bark (C:N ratio of 100:1 to 150:1) is added in the quantity needed to
regulate the moisture level of the compost. Modest departures from the ideal ratio
will slow composting, but will not stop the process. If your compost has an earthy
odor, it is close enough to the ideal ratio.
The C:N ratio of human urine is about 0.8:1, and that of raw sewage is about 7:1.
The C:N ratio of food scraps is variable, but tends to be less than 15:1.
pH range—The pH of the compost is important, because decomposer microbes are
intolerant of both acidic and alkaline conditions. The optimum pH range is between 6 and 7.5 (7.0 is neutral).
Fortunately, pH normally is not a concern for the compost operator if an appropriate
bulking agent is used. Altering the pH of a compost pile by adding lime to the crib, tank,
26—APPALACHIAN TRAIL CONFERENCE —BACKCOUNTRY SANITATION MANUAL
catcher, or composting bin (which makes the compost more alkaline) is not recommended.
The result is an increase in ammonia production with its resultant loss of nitrogen. Use
of peat moss to soak up excessive water tends to make the pile too acidic. Bark, wood
shavings, leaves, and duff should be added if peat moss is used.
3.3
DECOMPOSER
ORGANISMS
See Section 4—”Health and Safety
Issues.”
Aerobic bacteria, molds, fungi, and even protozoa found in soil use enzymatically
moderated chemical processes requiring oxygen to progressively break down feces
into water, carbon dioxide, nitrogen, and minerals. Antibiotics are produced by
some of these microorganisms (actinomyces species) in a microscopic form of germ
warfare. There is even a bacterium in soil (Bdellovibrio bacteriovorus) which attacks E. coli, a potential pathogen found in feces, and destroys it.
The process of transforming raw wastes to finished compost is the job of three major
forms of soil organisms: bacteria, fungi, and actinomycetes. The aim of composting
technology is to optimize conditions for growth of these organisms.
Dindal (1976) found soil invertebrate populations in composted
material to be the same as those in
the surrounding forest system. Most
are active burrowers and improve
aeration.
All three excrete enzymes which break down the large molecules of energy rich
organic compounds of sewage; smaller organic molecules and inorganic ions are
then absorbed over the entire microbe cell surface. Energy is released, raising the
temperature of the surroundings. The smaller absorbed molecules, such as sugars,
alcohols, organic acids, and amino acids, provide usable energy and food for cell
growth and reproduction.
Bacteria are single-celled organisms found everywhere. In terms of numbers, bacteria are the most prevalent organisms in the compost pile—a gram of compost
can contain more than one trillion bacteria. They are responsible for the initial
Figure 3.1—Types of decomposing organisms found in a composting toilet. Key organisms include actinomycetes, bacteria, and fungi. Red worms are a secondary player,
and must be added by the operator.” Drawing from The Composting Toilet System
Book by David Del Porto and Carol Steinfeld. Drawing originally published by D.L.
Dindal, Soil Ecologist, SUNY College of Environmental Science and Forestry, Syracuse, NY.
3: DECOMPOSTION AND COMPOSTING PROCESS—27
breakdown of a wide variety of compounds in the wastes, and for most of the heat
released into the compost pile.
Fungi are multicellular organisms with extensive networks of branching filaments.
They may make up the bulk of the compost mass during later stages of the compost process. They grow intermingled with actinomycetes, and they utilize similar substrates for energy and nutrient sources. Mature mushrooms often appear in
compost. Like bacteria, both fungi and actinomycetes are most active at temperatures below 55 degrees C. (130 degrees F.).
Actinomycetes are single-celled, mostly aerobic organisms, closely related to bacteria, but structurally similar to fungi. They function mainly in the breakdown of
cellulose and other organic residues resistant to bacterial attack. Several, such as
Streptomyces, produce antibiotics. Actinomycetes are detectable visually as a silvery blue-gray powdery layer in the compost, and by their faint earthy odor.
Many common soil animals invade the compost pile as decomposition proceeds.
Dindal (1976) found soil invertebrate populations in composted material to be
the same as those in the surrounding forest system. Most are active burrowers and
improve aeration. They feed on organic residues and microorganisms, in addition to each other, and further reprocess the wastes through digestion and defecation.
Some of the larger creatures commonly seen are beetles, collembolas (springtails), isopods, millipedes, mites, and slugs. Worms may burrow in compost at
moderate temperatures. Second-phase decomposition in a drying rack or moldering crib that has been capped provides the most favorable habitat for these larger
invertebrates.
3.4
Feces are rich in anaerobic organisms, such as E. coli, Bacterioides, Lactobacillus,
and Klebsiella, which typically account for about one-third the weight of the feces.
These bacteria produce mercaptans and other volatile compounds that account for
the unpleasant odor of feces.
CHARACTERISTICS OF
HUMAN WASTE AFFECTING
DECOMPOSITION
Medical literature indicates that feces are produced by an adult at a rate of about
150 grams (5 ounces) per day, a figure which agrees well with the records of the
Green Mountain Club (GMC). At our overnight sites with caretakers and batchbin composting toilets, each person has produced 0.03 gallons (3.85 ounces) of waste
per day, or 0.2 gallons per week.
GMC backcountry shelter-use data tabulated by Davis & Neubauer (1995) showed
that some overnight sites were collecting 14 gallons a week of waste, or more than
300 gallons a season. In 1999 Stratton Pond, GMC’s most heavily visited site on the
Appalachian Trail in southern Vermont, collected an average of 11 gallons of sewage per week. In the 20-week caretaker season, corresponding to the traditional
five-month hiking season, this totaled 220 gallons of waste.
Urine is mostly water. Of the 1,200 grams produced daily by an average person, only 60
grams are solids, mostly nitrogen as urea. Though this urea is a fairly small percentage of
urine by weight, it can be a major source of nitrogen in a compost operation.
Healthy people produce sterile urine. If, however, urine is allowed to percolate
through feces, it becomes a contaminated witches’ brew called leachate. Properly
designed composting toilets can adequately treat this leachate if it percolates slowly
See Davis & Neubauer (1995), in
Appendix E.
28—APPALACHIAN TRAIL CONFERENCE —BACKCOUNTRY SANITATION MANUAL
through an aerobic portion of the compost mass. But if a composting toilet is poorly
designed, operated without enough bulking agent, or overloaded, leachate will be
inadequately treated. It can then foul ground water and actually harm plants, so it
requires special handling.
3.4
DECOMPOSITION IN
TYPICAL BACKCOUNTRY
TOILETS
See Franceys, R. et al. (1992), in
Appendix E.
See Rybczynski et al. (1982), in
Appendix E.
Traditionally, people have used pit toilets or pit privies (commonly called outhouses)
in the backcountry. Returning to our cow pasture comparison, this practice is an
attempt to keep popular backcountry sites from resembling septic barnyards, or the
even more objectionable feedlot. Outhouses protect privacy and keep feces in one
spot, but the mass of feces and urine in the pit usually is anaerobic. Pit privies are
appropriate and effective in a low-use situation where a new pit may be required
every 4-6 years, although there is still the risk of groundwater contamination.
According to Franceys, pollution from a pit toilet can travel 15 meters (50 feet)
from the pit in the direction of groundwater flow. In dry soil, Rybczynski tells us
that pollution can travel from a pit toilet 3 meters (10 feet) vertically and 1 meter
(3 feet) laterally. Complete decomposition of feces in an underground pit may require decades. Human pathogens may remain viable for decades in the cool, anaerobic conditions of the pit. If soil is shallow, or groundwater high, pathogens and
nutrients can be transported from a site for many years after a pit has been abandoned. These facts preclude the use of pit toilets in many areas of the backcountry.
Composting systems, including composting toilets, require that feces remain aerated and in contact with soil organisms which can use oxygen to produce rapid
decomposition. If there is too much moisture, oxygen cannot reach aerobic bacteria, and they perish. If the volume of the fecal mass is too large compared to its
surface, the same thing happens; the center of the pile “goes anaerobic,” and malodorous, slow, anaerobic decomposition occurs.
With insufficient bulking agent, urine can saturate compost, causing anaerobes to take over. Anaerobic decomposition of the nitrogen in urine produces unpleasant chemicals such as ammonia, which
is poisonous in high concentrations and accounts for some of the
noxious odor of a traditional outhouse.
The nitrogen in urine requires a great deal of bulking agent to provide the additional carbon to achieve the optimal carbon:nitrogen
ratio for composting of 25:1, and to avoid saturation. Unless the
nitrogen is desired as a fertilizer, it is often undesirable to prematurely fill the chamber of a composting toilet or privy with the
large volume of carbonaceous material needed at a high-use backcountry site.
To minimize the labor of handling bulking materials and emptying
compost chambers, or if there is any uncertainty over the capacity
of a composting toilet or privy to treat leachate, it is best to separate urine and feces by providing urinals or asking users to urinate
in the woods.
Figure 3.2—Typical composting toilet process (moldering style) - Not
a specific unit mentioned in this manual. Drawing from The
Composting Toilet System Book by David Del Porto and Carol
Steinfeld.
4
Health and Safety Issues
Pete Ketcham, Field Supervisor, Green Mountain Club
Pete Rentz, M.D., Trails Chairman, Massachusetts A.T. Committee of
the AMC Berkshire Chapter
“Proper Sanitation is defined by the World Health Organization as any excreta disposal
facility that interrupts the transmission of fecal contaminants to humans.”
From The Humanure Handbook, by J.C. Jenkins, 1999
4.1
Various harmful disease-causing organisms, called pathogens, can be present in feces. Even the normally occurring E. coli can behave as a pathogen if it is ingested in
large volume, or if it contaminates a wound. Pathogens include diarrhea-causing
Salmonella or Typhoid bacteria, polio and hepatitis viruses, protozoa such as Giardia lambia and Entomoeba histolyticia, and parasites such as hookworm and Ascaris
(roundworm).
Most of these pathogens are killed by composting for several months, although Ascaris eggs can be resistant to composting conditions, and may remain viable for
years in favorable soil conditions. If aerobic decomposition is so fast that the temperature in a composting mass rises substantially, destruction of pathogens is more
rapid, and Ascaris eggs do not survive.
Hikers infected by Ascaris are probably rare in this country, though it would take a
very expensive study to determine this with certainty. However, there is no control
over who uses the backcountry toilets, and there is no practical method of monitoring the temperature in all parts of a composting chamber. Therefore, field workers
must assume that Ascaris eggs are present in compost even after high-temperature
decomposition, and they must follow the safety precautions and procedures outlined below.
Parasitic worms other than Ascaris are either tropical in habitat or not transmitted
through feces, and are of little concern in temperate climates. Giardia and their
OVERVIEW OF
PATHOGENS
30—APPALACHIAN TRAIL CONFERENCE —BACKCOUNTRY SANITATION MANUAL
cysts, amoebas, viruses, and pathogenic bacteria do not last long in the composting
environment.
4.2
CONDITIONS THAT
DESTROY PATHOGENS
AND PARASITES
Substantial elimination of human pathogens, including parasites, is the primary goal
of composting. A variety of interacting factors destroy pathogens; their importance
differs in mesophilic (low temperature) and thermophilic (high temperature)
composting.
The design and operation of a composting system depends on which type of
composting is expected to dominate. Batch-bin and beyond-the-bin systems rely
primarily on thermophilic composting for pathogen destruction, while moldering,
or continuous-composting systems rely on mesophilic composting.
The following conditions destroy pathogens in composting systems:
1. High temperatures generated in the interior of a compost pile in thermophilic
composting that exceed the upper limits of human pathogen tolerance.
Human pathogens, adapted to a narrow range centered around body temperature
(37 degrees C. or 98.6 degrees F.), are killed by exposure for several hours to
temperatures in the range of 50 to 60 degrees C. (122 to 140 degrees F.), or by
exposure for several days to temperatures in the range of 40 to 50 degrees C. (104
to 122 degrees F.).
See Section 9, “Batch-Bin Composting.
A properly managed compost pile, well-supplied with fresh material and large
enough to retain its own heat, will have enough nutrients and oxygen to warm
quickly into the thermophilic range. For specific information on optimum pile
size and management of thermophilic composting, see the description of BatchBin Composting in Section 9.
Thermophilic conditions are reached only in the interior of a pile. Therefore, in
any system that depends on high temperatures for pathogen destruction, the pile
must be turned to transfer the outside material to the interior. The greater the
Figure 4.1—Typical Pathogen Survival Rates at 20 to 30 Degrees Celsius in Various
Environments” From The Composting Toilet System Book by David Del Porto and
Carol Steinfeld.
4: HEALTH AND SAFETY ISSUES—31
volume of waste, the better the pile self-insulates, and the higher the proportion
of material that undergoes thermophilic conditions after each turning.
2. Aerobiosis: Most human gut pathogens are “obligate anaerobes” (organisms that
live only in the absence of oxygen). Aerobic conditions contribute to a lethal
environment for them. Small particle size and thorough mixing ensure maximum oxygen exposure.
3. Competition: Hardy local soil microbes are better able to utilize the rapidly changing
conditions in composting material in the competition for nutrients and attachment sites.
4. Destruction of nutrients: Human pathogens are generally more fastidious in their
nutritional requirements and choice of substrate than non-pathogenic organisms. They are at a competitive disadvantage as nutrients to which they are adapted
are consumed, oxidized or otherwise altered.
5. Antibiotics: Produced by actinomycetes and fungi, these hinder the growth of
many pathogens. Antibiotics play a larger role in the later stages of thermophilic
composting processes, when the pile has cooled and stable mesophilic conditions
favor fungi and actinomycetes.
6. Time: The length of exposure to inhospitable conditions takes a toll on human
pathogen populations.
Time is critical in a moldering toilet or privy, and in commercially produced
continuous-composting systems like the Bio-Sun or Clivus Multrum, since the
temperatures in these systems are in the mesophilic range. The agents and mechanisms of low-temperature pathogen destruction need ample time to take effect.
In a properly functioning compost pile, bacteria and viruses are generally inactivated over periods ranging from a few days to a few weeks. However, moldering
systems generally provide a large factor of safety by holding wastes in aerobic
conditions for months or even years.
Although composting occurs faster in batch-bin and beyond-the-bin systems,
time is still necessary. In the first (thermophilic) stage, wastes are exposed to
rapid aerobic composting conditions for three to six weeks. Most of the breakdown of waste materials and destruction of pathogens occurs in this phase. Aging
at ambient temperatures on a drying rack provides a secondary decomposition
period ranging from one month to one year, in which the compost stabilizes and
shrinks further. If more time is allotted to the primary phase, less is needed in the
secondary stage.
See Section 9.6—“Batch-Bin
Composting: The Finished Product,
and “Spreading Finished Compost.”
4.3
Although the ideal is to eliminate handling of raw sewage or reduce it to a minimum, compost operators often work with raw sewage. Even finished compost cannot be considered absolutely safe, although it typically has pathogen concentrations
comparable to those in ordinary forest soil. Strict sanitary procedures are essential.
If caution and common sense are used, the likelihood of infection or illness is extremely low.
The following precautions and procedures are essential in any operation composting
human waste:
SAFETY PRECAUTIONS
AND PROCEDURES
32—APPALACHIAN TRAIL CONFERENCE —BACKCOUNTRY SANITATION MANUAL
• Regardless of what type of system you are using, hang a special wash jug near the
outhouse, away from the shelter and washpit, and well away from surface water.
Label the jug “FOR COMPOSTING ONLY.” That wash jug should never leave
the site.
• The best container for a wash jug is a one-gallon plastic milk jug with a small
hole punched near the bottom. Put a small twig in the hole. When the jug is
capped and the twig is in place, leakage is slow. With the cap loosened and the
twig removed, a small stream comes out. That system allows you to wash and
rinse hands thoroughly.
• Use a clean jug to pour wash water into the wash jug before you begin any aspect
of the composting operation; never touch this clean jug after the point in the
work in which your hands may have become contaminated.
• The best soap is liquid antibacterial soap in a small squeeze bottle, although dish
washing soap also works well. Bar soap easily gets dirty. If bar soap is used, keep it
in a plastic soap dish. Do not leave soap outside on the ground, or critters may
chew a hole in the bottle or dish. Use your composting soap only for cleaning up
after composting operations. Label it “FOR COMPOSTING USE ONLY.”
• After handling any sewage container or performing any mixing or turning, always wash your hands well with soap. Allow soapy water from your hands to fall
directly on the ground.
• Do not put soap into clean water. Rather, let a small stream of clean water run
over your hands while sudsing up. Then rinse with clean water. This keeps the
wash container free of soap.
Figure 4.2—Things to always
do when handling composted
waste—Safety always comes
first.” From the Center for Clean
Development. Taken from The
Composting Toilet System Book
by David Del Porto and Carol
Steinfeld.
• Some compost operators follow their handwash and rinse by a rinse with a 3
percent hydrogen peroxide solution. This is a good precaution, since one never
knows whether people infected with pathogens have been using the toilet. A
dilute solution of liquid chlorine-based bleach (1 tablespoon per quart of water)
also can be used.
• Some people use the waterless hand sanitizer available from drug stores. While
useful, this is not a substitute for vigorous handwashing with water and antibacterial soap.
• Wear long pants.
• Long-sleeved shirts can be a problem, because the sleeves may
be soiled by brushing against soiled objects. Roll the sleeves up
snugly before you begin. Tuck in your shirttails so they won’t dangle
into or against a bin while you are turning compost. The same
goes for long braids. Any clothing used for composting should be
laundered in hot water separately from other clothing.
• During bug season, plan to do all work with your system early
in the morning. Swatting bugs or scratching insect bites with soiled
hands is foolish. Wear a bandanna to keep bugs out of your ears.
• Use rubber gloves. The Green Mountain Club (GMC) and
U.S. Forest Service (USFS) use heavy-duty rubber gloves, available from medical-supply stores. Wash your hands even when you
have used gloves.
4: HEALTH AND SAFETY ISSUES—33
• Keep your fingernails short.
• Wear eye protection. Safety glasses are the least-expensive option.
• Cover small cuts and blisters with Vaseline and a Band-Aid before you handle
any potentially contaminated objects, such as tool handles or handles on collection and storage containers. Remove Band-Aids and wash thoroughly when you
are done. Larger cuts are best covered with gauze and disposable gloves.
• If you cut or nick yourself while handling buckets or tools, stop and wash well
with soap and water. Bandage before finishing the job. Do not risk infection.
• Once you have begun interacting with your composting system, treat your hands
as if they are completely soiled. No adjusting of clothes, resting of hands on hips
or in pockets, folding of arms, etc. Keep your hands off your body, and touch
nothing but tools, containers, and bulking agent.
• If you accidentally splash raw sewage on yourself, wipe it off with dry bark powder or powdered charcoal, taking care to not scratch your skin. Then rinse with a
stream of water. Keep a small, open container of finely powdered bark or charcoal with you while you are working. Raw sewage can be removed the same way
from shoes or clothing, which should later be washed.
• Be careful if small, springy branches, or underwear with elastic gets into the sewage containers. This does happen occasionally. Elastic can slingshot sewage at
you with uncanny accuracy and alarming consequences.
• Keep your mouth closed while dumping sewage from one container into another.
If sewage does splash in your mouth, rinse immediately with copious quantities of
water, and do not swallow.
• Do not lean against any part of the composting system for leverage. Turn the
compost in the bin without touching the bin at all.
• Be careful to keep tool handles away from the sides of the toilet or any container.
• Keep all tool handles clean by rubbing them with bark or duff after use. Mark all
tools “FOR COMPOSTING USE ONLY” with paint or another permanent
marker. It is best to lock composting tools away from visitors.
• Stand tools up carefully to keep the handles clean. As an extra precaution, hold
tools well above where the metal tool head attaches to the wooden handle. The
metal portion of the turning fork and shovel will become contaminated during
each use.
• As a final precaution, never touch finished compost, no matter how “done” it appears. It is safe if properly handled. Areas where compost has been properly spread
should pose no health risk to the operator. However, take reasonable precautions
in moving through those areas (such as not walking in bare feet).
Additional safety equipment can be used. For example, the Randolph Mountain
Club, which operates the Bio-Sun continuous-composting toilets in the White
Mountains of New Hampshire, requires its volunteers and staff to wear heavy duty,
elbow-length, industrial-rubber gloves; plastic face shields, Tyvek shirts, and heavyduty rubber gowns.
See Section 11.6.
Part 2
Regulatory and Aesthetic Issues
5—Integrating Backcountry Sanitation and Local-Management Planning
6—Introduction to the Regulatory Process
7—The Aesthetics of Backcountry Sanitation Systems
5
Integrating Backcountry Sanitation and
Local Management Planning
Jody L. Bickel, Associate Regional Representative for Central and
Southwest Virginia, Appalachian Trail Conference
Since 1983, the Appalachian Trail Conference (ATC) has promoted local management planning among Trail-maintaining clubs and agency partners. The Comprehensive Plan for the Appalachian Trail and the Memorandum of Understanding between
the National Park Service and ATC (which delegated certain management responsibilities to ATC and the clubs) assume that local management plans will be the
cornerstones for cooperative management of the Appalachian Trail.
In 1987, ATC initiated the development of a local planning guide, with the intent
of providing the Trail-maintaining clubs with a comprehensive reference document
to aid them in the process of local planning. The Local Management Planning Guide
has evolved from this initial concept to with two purposes: (1) to consolidate existing ATC and federal policies affecting Trail management into a single reference for
clubs and cooperating agencies, and (2) to answer questions on how to prepare a
local management plan and what to include in a plan. In other words, the Planning
Guide is designed to be used as both an active tool and as a permanent reference of
current policies for management of the Appalachian Trail.
Each of the 31 Trail-maintaining clubs prepares a local management plan, following
the guidelines in the planning guide, for its section of the Trail. The most current
edition of the Planning Guide was revised in 1997. Each club plan is reviewed by
the ATC Board of Managers and updated approximately every five years.
See Appendix D.
When making decisions about backcountry sanitation management, volunteers
should refer to the maintaining club’s local management plan to ensure compliance
with local standards and Trail-wide policy. For more information contact your ATC
regional office.
6
Introduction to the Regulatory Process
Pete Irvine, Appalachian Trail Coordinator, USDA Forest Service
6.1
Providing adequate facilities for the disposal of human waste along the Appalachian National Scenic Trail is a complex issue. Factors including the number of
users, type of users (day hikers, overnighters, long-distance hikers), length of the
annual use season, availability of nearby off-Trail facilities, type of terrain, availability of suitable overnight sites (both shelters and campsites), and other variables, all
contribute to this complexity.
OVERVIEW
In many locations along the Trail, dispersed individual cat-holing of human waste
in accordance with the principles of Leave No Trace is the current sanitation practice, and is expected to be adequate and acceptable for the foreseeable future. In
other locations, concentration of use, particularly overnight use, on a limited number of sites—especially in fragile or sensitive ecosystems—dictates the need for more
developed sanitation facilities.
6.2
There is no “standard policy” among the various Appalachian Trail cooperative
management partners addressing backcountry sanitation facilities. The current Appalachian Trail Conference (ATC) policy, as stated in the Local Management Planning Guide (1997 Edition) is that sanitation facilities should be provided at high-use
shelters and popular campsites. Some clubs (via their local management plans) or
regional management committees have additional policies.
For example, the mid-Atlantic regional management committee has resolved that
all overnight shelter sites in its region should have developed sanitation facilities.
Trail clubs in that region (Shenandoah National Park in Virginia through New
York) have worked for several years to develop waste facilities at existing shelters
that do not have them.
The policies of federal and state agency partners vary, and often include general,
agency-wide policy direction (for example, USDA Forest Service manuals and hand-
CURRENT POLICIES
ADDRESSING BACKCOUNTRY SANITATION
See: Local Management Planning
Guide (1997 Edition), in Appendix E.
38—APPALACHIAN TRAIL CONFERENCE —BACKCOUNTRY SANITATION MANUAL
books, National Park Service director’s orders, and state agency equivalents). They
often include additional, more specific policy for particular units (forests or parks),
or for the Appalachian Trail (for example, national forest land management plans,
national park general management plans, and state agency equivalents).
Both Forest Service and Park Service policies state that wastewater facilities will be
in compliance with the federal Clean Water Act. Both agencies strongly recommend involvement of appropriate specialists (such as a public health service consultant or sanitary engineer) in determining the appropriate type of facility type, its
design, and its siting. According to Park Service policy, the following are suitable
backcountry waste systems:
•
•
•
•
•
•
Flush toilets
Composting toilets
Barrel toilets
Evaporator toilets
Incinerator toilets
Pit privies
The overriding legislation dealing with backcountry sanitation is the Clean Water
Act of 1977, as amended. This law gives the United States Environmental Protection Agency (EPA) the authority to regulate wastewater facilities in order to restore
and maintain the integrity of the nation’s waters. EPA delegates many of the permitting, administrative, and enforcement aspects of the law to state governments,
who in turn work through local (county, township, or municipal) sanitarians and
health departments. While federal agencies are not bound by most local and state
laws and regulations, they are bound by the federal regulations pursuant to the Clean
Water Act which are administered by state and local agencies for the EPA.
6.3
CURRENT PROCESSES
FOR PROPOSING
SANITARY FACILITIES
A proposal to develop a human waste facility at a site may be advanced by any of the
cooperative management partners—individual maintainer, local maintaining club,
ATC, or land-managing agency partner. Often, a proposal for a human waste facility is part of a larger proposal to construct or reconstruct an overnight site. Once a
proposal is advanced, all cooperative management partners should be involved in
the decision: first, whether a human waste facility is necessary or desirable; and
second, what facility is best suited to the location.
Once a proposal for a sanitary facility has been developed by the management partners, land ownership determines the direction that the approval process will take.
On federal lands, an environmental analysis of the proposal must be conducted in
accordance with the National Environmental Policy Act of 1969 (NEPA), which
requires activities be analyzed to determine their impacts on natural resources and
the public.
In increasing order of complexity, the three levels of analysis are: (1) categorical
exclusion, (2) environmental assessment, and (3) environmental impact statement. Most
simple actions, like relocating or improving an existing privy, can be done under
the easiest procedure, a categorical exclusion. Involvement of program-area specialists is usually required to ensure that the project will not adversely affect cultural
resource sites or threatened or endangered species, and that it is compatible with
other activities. Investigation of agency, state and local requirements should be completed early in the NEPA process.
6: INTRODUCTION TO THE REGULATORY PROCESS—39
The Park Service and the Forest Service have developed different policies to implement the requirements of NEPA that depend, in part, upon site-specific factors and
the risk assessment of the decision maker (such as the district ranger, the forest
supervisor, the park manager, or the park superintendent).
On non-federal lands, analyses and approvals may be required by other agencies,
and coordination with other state and local regulatory agencies may be necessary.
The applicable state and local regulatory agencies vary from state to state.
For example, state regulations in Maryland and Pennsylvania, which prohibit the
direct ground contact of human waste in a constructed facility, preclude new pit
privies. Concrete vault toilets and composting toilets with waterproof composting
chambers meet the regulations.
Construction of a replacement shelter and composting toilet in Pennsylvania in
1997 required approval of the concept and design of both the shelter and the toilet
by the land manager, the Pennsylvania Game Commission, and separate approval
of a permit for the composting toilet by the local sanitary engineer.
In 2000, the Green Mountain Club (GMC) in conjunction with the University of
Vermont and the Vermont Department of Forests, Parks, and Recreation restored
the historic Butler Lodge on Mt. Mansfield. This project also included an upgrade
of the batch-bin composting toilet system to a beyond-the-bin liquid management
system. The project required submitting a wastewater permit application to the State
of Vermont Agency of Natural Resources Department of Water Supply and Wastewater Disposal. The GMC submitted an application and a thorough explanation of
the system, based on the report developed by the Appalachian Mountain Club
(AMC). A permit was issued. This is the first time the GMC has had to apply for
such a permit. (See Appendix for the permit.)
See Appendix N for the permit.
The Appalachian Mountain Club is planning to install red worm moldering privies
at several sites on the A.T. in Connecticut. In order to begin the process of getting
regulatory acceptance of these systems, AMC wrote a letter to the State of Connecticut Department of Public Health. The club was placed in contact with the
supervising sanitary engineer of the Environmental Engineering Section. The AMC
submitted a letter of request accompanied by a detailed description of the moldering
privy. The state approved the installation as long as several criteria were met. The
state’s letter served as the AMC Trails Committee’s means of notifying local health
agencies of the acceptability of the system and to solicit their involvement in the
review, testing, and approval of the units where applicable.
See Appendix N for the state’s
letter.
The Appalachian Trail Conference and its local maintaining clubs for the Great
Smoky Mountains National Park area are working to install moldering privies along
the A.T. in 2001. They are working closely with the National Park Service to make
sure that all applicable regulations are met. For example, in the national park, regulations concerning introduced and exotic species will bar the ATC and clubs from
using red worms in the moldering privies.
Determine all of the regulatory stakeholders that need to be involved in your proposed
sanitation project!
The importance of this cannot be emphasized strongly enough. Management of the
Appalachian National Scenic Trail is a partnership. Volunteers have always been—
and continue to be—the cornerstone of the A.T., but they do not work alone. Since
the 1920s, the Forest Service, the Park Service, the states and local communities
have worked together to complete, preserve, and maintain the Trail.
40—APPALACHIAN TRAIL CONFERENCE —BACKCOUNTRY SANITATION MANUAL
The 1978 amendment to the National Scenic Trails System Act authorized the
A.T. land acquisition program, which dramatically broadened and deepened this
partnership. Today, volunteers work in a partnership that includes the Appalachian
Trail Conference (ATC), Trail maintaining clubs, and multiple government landowning agencies (NPS, USFS, state parks, Department of Transportation, local Trail
communities, etc.).
Contact your ATC regional office for
more information; addresses are in
Appendix D. Also see Appendix C
for regulatory contacts, which can
inform you of all of the stakeholders involved with permitting a sanitation system.
Even more partners are involved in backcountry sanitation. These included state,
county, and local health departments, state agencies in charge of natural resources
and environmental conservation and protection, and state, county, or town-contracted engineers. Contact your ATC regional office for more information; addresses
are in the Appendix. Also see the Appendix for regulatory contacts, which can
inform you of all of the stakeholders involved with permitting a sanitation system.
Some volunteers feel challenged by working in this larger partnership. Government
and state agencies must comply with many laws, which sometimes slows approval of
a project. However, this partnership creates a system of checks and balances that
ensures the overall best trail management. It also provides the trail management
community access to a vast pool of talent and experience. Without everyone’s commitment to work together, the health and preservation of the trail could be threatened.
How do you learn what you need to know? The best way is from your club’s leadership. The partners’ rights and obligations are in each club’s local management plan,
itself authorized by federal agencies under the Comprehensive Plan for the Management of the Appalachian Trail. If you are not part of a club, consult the Appalachian
Trail Conference. ATC develops policies that ensure consistent and thoughtful management of the trail and its corridor lands. ATC alternately supplies the bond to
hold everything together and the lubricant to make the partnerships along the trail
work smoothly.
Appalachian Trail Design, Construction, and Maintenance, Second Edition, by William Birchard, Jr.
and Robert D. Proudman, published by the Appalachian Trail Conference, Harpers Ferry WV 2000,
pp. 10-11.
In any case, don’t start any backcountry sanitation project on your own. Trail work
on the A.T. often requires a formal authorization from the Park Service, Forest Service or state, so always work with the blessing of your club and the ATC.
For more information, see Appalachian Trail Design, Construction, and Maintenance,
Second Edition,by William Birchard, Jr. and Robert D. Proudman.
6.4
ADDITIONAL REGULATORY
CONSIDERATIONS
To go along with the usual regulatory process for sanitation projects along the A.T.
described above, the following situations require additional consideration before
work begins:
Congressionally designated Wilderness—New structures are prohibited in most
designated federal Wildernesses, in keeping with the Wilderness Act of 1964 and
other Wilderness legislation. Existing Appalachian Trail structures in Wilderness
are generally allowed to remain and be maintained, but complete reconstruction or
new construction may be prohibited. It is prudent to consult the legislation establishing each Wilderness, because the legislation (and the committee language used
to assist in its interpretation) usually varies from one Wilderness to another. Even if
construction or reconstruction is permitted, use of vehicles and other motorized
equipment generally is prohibited. Helicopter delivery of material and removal of
waste may be permitted, but if so, it is strictly regulated.
6: INTRODUCTION TO THE REGULATORY PROCESS—41
Special areas designation—Designation of state or federal land areas as roadless
areas, research natural areas, or other specially designated areas may limit the options for construction of facilities, or vehicular or air access to waste management
facilities for maintenance.
Design approvals—Most agency land managers require that construction plans be
developed for agency approval. Agency resources, including engineers and landscape architects, may be available or required to assist in design. Efforts spent on
design approval, including accessibility and confined space considerations, can prevent or reduce problems during construction and operation of the facility.
Accessibility—Accessibility for people with disabilities must be considered in planning and designing all facilities on federal or state land, regardless of remoteness or
difficulty of access to a site. Applicable legislation includes the Architectural Barriers Act of 1968, the Rehabilitation Act of 1973, and the Americans with Disabilities Act of 1990. Any facility constructed using federal funds must be made accessible, and all federal programs must provide for reasonable accommodation for persons with disabilities in all program areas. Accessibility requirements should be researched early in the development of a facility.
At the time of publication of this manual, new regulations on access for disabled
persons in outdoor environments, including backcountry settings, were being developed by the Architectural and Transportation Barriers Compliance Board, but
were not yet finalized. Agency land managers are the best source of current accessibility information.
Confined spaces—A backcountry sanitation facility with an access hatch, ladder,
steep stairs, low head room, or other egress or exit restriction is a “confined space” as
defined by the Occupational Safety and Health Administration (OSHA), and special regulations apply. Sanitation facilities, especially composting systems, may present
these situations. The OSHA regulations are difficult to follow in backcountry situations, and the best practice is to avoid confined spaces when designing a backcountry
sanitary facility.
Agency land managers are the best source for information on confined space requirements.
Disposal of compost—The disposal of composted material is regulated by the EPA.
In general, composted material should be considered “domestic septage,” like that
from a septic tank, unless temperature is monitored throughout the composting process, or pathogen tests of the finished compost categorize it as “Class A sludge.” EPA
regulations require that domestic septage be incorporated into the soil when placed
on the land, while Class A sludge may be surface-applied without restriction. Remote backcountry composting toilets have been shown capable of producing Class
A sludge even in the absence of high composting temperatures, and it is possible to
obtain waivers from domestic land application requirements from the EPA-designated regulating agency.
Maintainer health and safety—Personnel, whether volunteer or employee, involved
with the maintenance of backcountry sanitation facilities should be aware of current agency standards and use standard practices and appropriate protective equipment. Standards and practices vary by agency, and local land managers are the best
source of current standards and practices.
For more information on regulatory processes, contact your ATC regional office.
7
The Aesthetics of Backcountry
Sanitation Systems
Jody L. Bickel, Associate Regional Representative for Central and
Southwest Virginia, Appalachian Trail Conference
7.1
OVERVIEW
Managers of the Appalachian Trail are increasingly challenged to provide both adequate sanitation facilities and a primitive experience. An overnight backcountry
site can be overwhelmed by an imposing waste management system that can destroy
the sense of solitude and isolation from civilization.
Trail managers should carefully consider the aesthetics of each potential sanitation
system, along with issues such as user types and seasonal use patterns. Factors such
as location, design, installation and maintenance affect aesthetic impacts directly,
and also indirectly through their effects on user compliance. Designated “toilet areas” and throne-like toilets with large buildings and extensive equipment should be
avoided if possible.
High use, particularly in fragile ecosystems, has encouraged development of more
effective, but also more elaborate, waste management systems. These include commercially produced continuous-composting toilets (sometimes with solar-assisted
warming and ventilation) and batch-bin composting systems. Such systems generally require a larger structure footprint, additional tools, compost bulking materials,
and extraneous system supplies. Appropriate tools and supplies are necessary for
system management, but an overabundance can create adverse aesthetic impacts.
7.2
GUIDELINES ON
AESTHETICS
The Appalachian Trail Conference (ATC) provides guidelines on aesthetics in several documents, which should be used in addition to this manual.
Chapter 2(I) of The Local Management Planning Guide (1997 edition), which details
ATC and federal policy on Trail management, provides some guidance on aesthetics. It is quoted below.
7: AESTHETICS OF BACKCOUNTRY SANITATION SYSTEMS—43
In 1995, ATC’s Board of Managers adopted the following policy on managing the
A.T. for a primitive experience:
The Appalachian Trail Conference should take into account the effects of Trailmanagement programs and polices on the primitive and natural qualities of the A.T.
and the primitive recreational experience the Trail is intended to provide. Although
these guidelines are intended to apply primarily to the effects of actions or programs
on predominantly natural, wild, and remote environments along the Trail, they may
apply to certain pastoral, cultural, and rural landscapes as well.
Trail improvements, including shelters, privies, bridges, and other facilities, should
be constructed only when appropriate to protect the resource or provide a minimum
level of public safety. Design and construction of these facilities should reflect an
awareness of, and harmony with, the Trail’s primitive qualities. Materials and design
features should emphasize simplicity and not detract from the predominant sense of a
natural, primitive environment. The Trail treadway, when constructed, reconstructed,
or relocated, should wear lightly on the land and be built primarily to provide greater
protection for the Trail footpath or Trail resource values. Trail-management
publications should include appropriate references to the potential effects of Trailmanagement activities on the primitive qualities of the Trail.
In developing programs to maintain open areas, improve water sources, provide
sanitation, remove structures, and construct bridges, signs, Trailheads, and other
facilities, Trail managers should consider whether a proposed action or program will
have an adverse effect on the primitive qualities of the Trail, and, if such effects are
identified, whether the action or program is appropriate.
Trail clubs also should consider the effects of individual management actions (such
as bridges, relocations, or other developments) on the primitive character of the Trail.
The remote recreational experience provided by the Trail and the resources that
enhance this experience should be carefully considered and protected. The following
questions can be used to help evaluate the potential effect of a policy, program, or
project on the primitive quality of the Trail:
• Will this action or program protect the A.T.?
• Can this be done in a less obtrusive manner?
• Does this action unnecessarily sacrifice aspects of the Trail that provide solitude or
that challenge hikers’ skill or stamina?
• Could this action, either by itself or in concert with other actions, result in an inappropriate diminution of the primitive quality of the Trail?
• Will this action help to ensure that future generations of hikers will be able to enjoy a
primitive recreational experience on the A.T.?
— Local Management Planning Guide (1997 edition), Chapter 2(I)
7.3
The Checklist for the Location, Construction and Maintenance of Campsites and Shelters
on the Appalachian Trail is a listing of important factors to consider when locating
and building new campsites and shelters, or for operating and maintaining older
sites. Since most backcountry sanitation facilities are located at designated overnight-use areas, this document can serve as a useful planning tool.
FACTORS IN LOCATING
SANITATION FACILITIES
44—APPALACHIAN TRAIL CONFERENCE —BACKCOUNTRY SANITATION MANUAL
See: Checklist for the Location,
Construction and Maintenance of
Campsites and Shelters on the Appalachian Trail.
Consider the following factors that affect the aesthetic impact of sanitation facilities:
Toilet location—If possible, choose an unobtrusive location, so the toilet will not
dominate the site. To encourage user compliance, choose a dry site with a dry access
route, and consider distance from camp area(s), rodent pests, and wind and sun
exposure. Prevent numerous access trails to the toilet by clearing and marking one
defined route.
Number of toilet facilities per site—One managed facility is adequate for most
shelters and campsites. Consider consolidating multiple existing systems. However,
bear in mind that overloading a single facility during peak season may actually reduce user compliance.
Toilet design—Use rustic design and materials, subject to the need for durability
(for example, use galvanized hardware and nails). When items such as plastic or
metal bins and plastic pipe must be used, camouflage or disguise them through creative construction and installation. Stain or paint structure(s) with colors that harmonize with the site, such as brown, dark green or gray at forested sites. Do not use
glossy paint. Assure that the roof and flashing are flat, muted and non-reflecting.
Avoid over-building the structure and sanitation area with unnecessary items, such
as windows and benches.
Contamination prevention—Small wild animals, such as mice, voles, and squirrels,
as well as domestic pets, are tempted to explore sanitation management areas. Mice,
in particular, like to use toilet paper—new and used—for nesting material, and will
carry it into a nearby shelter. Install hardware cloth to block access to raw waste. Do
not provide toilet paper for users. Although complete access prevention is not possible, keeping a clean, managed toilet located a decent distance from camp and
cook areas will help.
People are often very curious about structures in the backcountry. Generally, the
less obtrusive a sanitation system is, the less attention it will attract. Although most
people will keep their distance from the inner workings of a toilet, managers should
guard against system disturbance by Trail visitors. Typical problems include use of
bulking material (such as shavings or bark mulch) for fires, use of shovels and other
sanitation tools around campsites, and disturbance of equipment (unlatched bins,
etc.). Post low-impact signs at the management area explaining the hazards of the
waste system. Cover tools and supplies with earth-toned tarps out of sight of the
area. In high-use areas, consider padlocking all sanitation tools in a storage locker
attached to or included in the toilet structure.
See Appendix D.
For more information, contact your ATC regional office.
Part 3
Descriptions of Systems
8—The Moldering Privy
9—Batch-Bin Composting
10—Liquid Separation in Composting Systems
8
The Moldering Privy
Pete Ketcham, Field Supervisor, Green Mountain Club
Dick Andrews, Volunteer, Green Mountain Club
8.1
INTRODUCTION
The moldering privy is experimental, but it has great promise for disposal of human
waste in the backcountry, and even in some frontcountry locations. It is much cheaper
than commercially manufactured composting toilets. The moldering privy requires
less labor and exposes maintainers to less risk of infection than bin composting
systems, and is much less polluting than pit toilets. It also eliminates the need to dig
new pits, and it can serve a higher volume of users than pit toilets. The maximum
use capacity of the moldering privy has not been established, but it may approach or
equal the capacity of commercial composting toilets and batch-bin composting systems.
The moldering privy could serve as the perfect middle ground for maintainers. It
combines the resource protection benefits of composting with less maintenance,
expense and risk than earlier systems.
Project background—The moldering privy was developed in a continuing research
project by the Green Mountain Club (GMC) in conjunction with the Appalachian
Trail Conference (ATC), the National Park Service Appalachian Trail Park Office
(ATPO), and the Vermont Department of Forests, Parks, and Recreation (VT FPR).
The goal was to develop a waste management system to replace the traditional pit
toilet and designated toilet (cathole) area with a system that manages human waste
with less maintenance than other composting systems.
GMC drew upon the concept for the moldering privy from Dick Andrews (a GMC
volunteer, composting toilet owner, and the editor of this manual) as well as existing composting technologies and literature on the subject of sanitation in remote
backcountry areas. Dick conceived of, and built, the first moldering privy on the
Long Trail/Appalachian Trail at Little Rock Pond in the Green Mountains of Vermont in 1997.
8: THE MOLDERING PRIVY—47
In 1999, with the assistance of the GMC’s agency partners, the club created a refined version of the moldering privy with plans for a lightweight outhouse suited to
backcountry applications, and built four units on the Long Trail in northern Vermont. The GMC also produced a draft Moldering Privy Manual and Design in 1999.
In 2000, the GMC designed a double-chambered moldering privy, and installed
three experimental double units on the Long Trail. The lessons we have learned and
the improvements we made are presented in this chapter.
Other clubs have also been experimenting with the moldering privy concept. For
information on the AMC-Berkshire A.T. Committee’s experience, see Chapter 8—
Case Studies, Moldering Privy on the A.T. in Massachusetts.
Chapter 8—Case Studies, Moldering Privy on the A.T. in Massachusetts.
Note: A word of caution—The GMC moldering privy system is still experimental. Composting in our moldering privies has been so effective that no composting
chambers have yet filled, so we have not completed a full composting cycle. It
may take several more seasons to fill our current systems and finish composting
their contents.
Therefore, GMC suggests considering all the waste management systems in this
manual that have proven track records. If the alternatives to the moldering privy
do not work for you, experimenting with the moldering privy may be your best
option. Please keep in touch with the GMC periodically to see how our systems
are working.
A moldering privy built by the Appalachian Mountain Club (AMC) Berkshire
Chapter’s Massachusetts A.T. Committee has completed more than one full
composting cycle, with excellent results. For details, see Chapter 8—Case Studies, Moldering Privy on the A.T. in Massachusetts.
For details, see Chapter 8—Case
Studies, Moldering Privy on the A.T.
in Massachusetts.
8.2
Batch-bin composting has worked well in many sites, but it requires a lot of labor,
both by well-trained and sturdy people to manipulate the process, and by porters
with strong backs to haul in the large amounts of bark mulch or other bulking agent
needed to absorb liquid. Batch-bin composting also requires field personnel to handle
raw sewage. With care, this can be done with reasonable safety, but it still poses a
risk that is better avoided. In addition, batch-bin composting kills pathogens very
effectively in waste that has reached a high temperature, but if part of the waste in
a batch fails to heat sufficiently, pathogens will survive. In practice, the odds are
high that part of the waste will escape high temperatures. The practice of finishing
compost on drying racks was developed to address this limitation.
The moldering privy was inspired by commercially manufactured ambient-temperature, continuous-composting toilets designed for households, with the realization
that in most backcountry settings the soil—though sometimes thin—is adequate to
absorb the extremely low volumes of liquid deposited in a waterless toilet. Thus, the
watertight, bulky and expensive composting chambers characteristic of household
composting toilets are not needed in the backcountry.
RATIONALE FOR
DEVELOPMENT OF THE
MOLDERING PRIVY
48—APPALACHIAN TRAIL CONFERENCE —BACKCOUNTRY SANITATION MANUAL
8.3
WHAT A MOLDERING
PRIVY IS
Jenkins (The Humanure Handbook,
1994)
What moldering is—Moldering means slow, or cool, composting. This is in contrast to quick, or hot, composting, which is the process on which a batch-bin
composting system relies. As defined by Jenkins (The Humanure Handbook, 1994),
to molder means “to slowly decay, generally at temperatures below that of the human body.”
The temperature range of a moldering pile of waste is between 4 degrees C. and 37
degrees C. (between 40 degrees F. and 99 degrees F.). Temperatures below 4 degrees
C. (40 degrees F.) do not accommodate the invertebrates and microorganisms that
process fecal material. Temperatures above 37 degrees C. (99 degrees F.) are in the
thermophilic range of composting, which is generally not possible without a large
amount of fresh organic material and a lot of human manipulation of the pile. Waste
is added too slowly in a continuously moldering toilet to provide enough fresh organic fuel to reach a high temperature, and the moldering privy aims to avoid the
labor of frequent manipulation of the pile.
Below 20 degrees C. (68 degrees F.), decomposition slows as the temperature drops,
until the pile is dormant below 4 degrees C. (40 degrees F.). The pile does not freeze
at 0 degrees C. (32 degrees F.), because it contains dissolved salts and other minerals, but it does freeze below about -2 degrees C. (29 degrees F.). Composting organisms survive freezing, or they leave eggs or spores that survive freezing. When the
temperature rises above 4 degrees C. (40 degrees F.) again, the organisms become
active again, or their eggs and spores hatch, and composting resumes.
How it is designed—A moldering privy consists of:
• A conventional privy shelter, or outhouse, on a crib.
• The crib sits above a shallow depression, only a few inches deep, which confines
urine so it will percolate into the biologically active layer of the soil.
• The pile of human waste mixed with bulking agent in the crib is above ground,
so it cannot become waterlogged.
• Gaps between timbers in the cribbing are covered with screening, forest duff, or
both, to exclude flying insects and sunlight, but to allow infiltration of air. Hardware cloth or other barriers may be desirable to exclude rodents, which sometimes take toilet paper to dry structures and use it for nesting material. This can
be a problem with any toilet other than a flush toilet.
• Native microorganisms and invertebrates, possibly supplemented by introduced
red wiggler worms (also known as redworms or manure worms), do the real work
of composting.
Many design variations are possible, and creative thinking will yield one to suit
almost any condition. A single crib with two or more sections can support a shelter
that can be slid back and forth among the sections on skids. In high-use sites, a
shelter can be moved among three, four or more cribs to allow a year or more for
complete composting before returning the shelter to the first crib.
The crib can be built in many ways, but it there are some advantages to constructing
it with a pyramidal form, wider at the base than at the top. This shape is more
stable; it holds more volume for a given height; it provides more soil surface at the
base to absorb liquids; it facilitates banking duff or straw against the sides (which
blocks light and drying breezes while admitting adequate air and helping to keep
8: THE MOLDERING PRIVY—49
Figure 8.1—Conceptual diagram for the Green Mountain Club moldering privy. Not to scale. This diagram shows only one
composting chamber. Current Green Mountain Club design utilizes a double-chambered system. When one chamber is full
in the new design, it is capped with a lid, and the outhouse building is shifted over the empty chamber.” Drawing from Lars
Botzojorns, Pete Ketcham, and the Green Mountain Club.
50—APPALACHIAN TRAIL CONFERENCE —BACKCOUNTRY SANITATION MANUAL
the pile warm in cool weather); and it reduces contact between the crib and the
compost pile, which prolongs the life of the crib. However, a crib with vertical sides
is somewhat easier to build, and this advantage may be most important to some
builders.
How it is used—Users are asked to add a small amount of bulking agent with each
use. The bulking agent need not be kept dry since, unlike batch-bin composting, it
need not absorb liquid. If users add too much bulking agent, it will do no harm,
except that the crib will fill faster. Occasional stirring of the pile, adding bulking
agent if necessary, plus regular light watering to keep it moist, is the only manipulation required to optimize composting. Moderate overwatering will do no harm, since
excess water will simply seep into the soil.
Unlike pit privies and batch-bin composting operations, which usually ask users to
urinate in the woods (to reduce odors and to minimize the amount of bulking agent
needed to absorb liquid), at all but the highest use levels, separation of urine from
the compost mass is unnecessary in a moldering privy, which actually benefits from
the liquid provided by urine.
A generous layer of bulking agent (six inches to a foot) is spread on the bottom of
the privy crib when it is built, to insure that liquids will filter through an aerated
layer before reaching the soil. This layer is topped with some decomposed leaf litter,
or forest duff, to introduce local decomposer organisms. Liquid that seeps through
the pile will be contaminated with pathogens from feces, but if it percolates slowly
enough through aerobic and active regions in the lower part of the pile, it will be
treated by contact with air and aerobic micro-organisms. If pathogens are not entirely eradicated in the composting pile, liquid receives further treatment in the
biologically active upper layer of soil into which it seeps.
Capacity—The crib can easily be made to enclose substantially more volume than
the pit of a typical backcountry pit privy, and composting reduces the volume of
waste, so moldering privies fill more slowly than most pit privies. In low-use sites,
composting may be fast enough to keep up with use for many years, or even indefinitely.
See Section 11.8—Case Studies,
“Prototype Wood-Fired Compost
Incinerator.”
If and when the crib does fill, a new crib is built nearby, and the privy shelter moved
to it. The old compost pile is covered with light and porous organic material, typically half a foot or more of duff, straw, or shavings, possibly topped by a layer of
hardware cloth (to exclude rodents). At some sites, the cover may need secure fastening to exclude curious people. The cover is intentionally porous to admit rainwater to keep the pile moist; it is lightweight to avoid compacting the pile. In humid climates, the pile may stay damp enough to finish composting even if it is fitted
with a solid cover. In dry climates, the covered pile may need occasional watering.
Recycling compost—When the second crib is full, typically after several more years,
the finished compost in the first crib can be removed and applied to the forest floor,
either on the surface away from human traffic and water, or by shallow burial. If
required by local regulations, compost can be dried and removed from the backcountry. With the right equipment, it can also be incinerated on the spot, yielding
a small amount of sterile ash. The shelter is returned to the first crib, and the second
crib is covered for further composting and aging.
An incidental advantage of a privy on a raised crib rather than at ground level is
that the outhouse door can be opened without clearing snow for much or all of the
winter, so it is more likely to be used in winter. The pile will freeze in winter, but
composting will resume when it thaws.
8: THE MOLDERING PRIVY—51
Use of bulking agent—Because there is no need for the bulking agent to absorb
urine, much less bulking agent is necessary than in batch-bin composting. At many
sites, enough forest duff is available to supply the bulking agent for a moldering
privy. Of course, duff should be collected from various spots in rotation to avoid
adverse impacts on the area’s soil natural community.
Even when duff is scarce, carrying in bulking agent is much less arduous than with
batch-bin composting. Shavings have been found to work well, since they are light
to carry and resist compaction. Both hardwood and softwood shavings work, although some people consider hardwood shavings superior. Feed stores sell baled
shavings as bedding for horses and other livestock, or shavings may be available free
or inexpensively at lumber mills. Sawdust (unless very coarse), hay, straw, and
unrotted leaves or conifer needles all tend to compact and form impermeable layers,
so they are less satisfactory. Conifer needles also are likely to be too acidic; so is peat
moss. Wood chips are usually insufficiently absorbent, and are hard to mix with
hand tools.
Monitoring—The composting process in a moldering privy takes place at ambient
temperature, so there is no need for monitoring and management of the process,
except possibly for some turning and watering of the pile. It is useful to build the
toilet bench or stool with a hinged top, so the whole top can be flipped up to make
stirring or watering the pile easier. It is even better to build the shelter with a removable toilet stool and chute, such as many National Forest privies have, since it
is easier to manipulate the pile through a hole at floor level.
Venting—There is no need to install a vent stack in a moldering privy shelter, since
the permeable sides of the crib admit plenty of air, and obnoxious gases are not
produced in aerobic composting. Vent stacks in pit privies normally do nothing
useful anyway, since there is nothing to create a draft. They are installed in a tradition that began in the days of anaerobic urban cesspool privies that encountered
such high levels of use that they produced large volumes of explosive methane (the
principal constituent of natural gas). Methane is much lighter than air, so it readily
rises up a vent stack and dissipates. Backcountry pit privies produce insignificant
amounts of methane, so the vent stacks we are accustomed to seeing on them are
ineffective and superfluous.
Redworms in moldering privies—Experience in household composting toilets has
shown that adding red wiggler worms substantially speeds and improves low-temperature composting, and this is true in backcountry moldering privies as well. The
worms consume waste, aerate the pile, and spread microorganisms and spores throughout the pile. Worms also can tunnel through and aerate compacted layers if they
develop in the pile.
There is not yet enough experience to know whether redworms or their eggs can
survive winters in a privy, although they normally do in large manure piles. Therefore, clubs experimenting with them have been re-introducing them each spring.
Predators such as shrews may sometimes eliminate introduced worm populations.
Fortunately, composting will proceed even without worms, although it may be slower
and require more manipulation of the pile.
Trash—If trash tossed into a moldering privy is inconvenient to remove, it can
simply be left there until composting is complete, and then removed. Since material
in a moldering privy needs little or no handling until composting is finished, trash
does not hinder the process as it does in batch-bin composting. Of course, trash
takes up space in the crib, so it should be discouraged.
52—APPALACHIAN TRAIL CONFERENCE —BACKCOUNTRY SANITATION MANUAL
Figure 8.2 —Diagram and text from The Composting Toilet System Book by David Del
Porto and Carol Steinfeld.
Food scraps introduced in a moldering privy actually would improve the composting
process, by providing a more diverse nutrient supply for the composting organisms.
However, they attract pests—flies, rodents, possums, skunks, raccoons and bears—
so they are undesirable, and should be prohibited by stewardship signs.
8.4
ABOUT THE RED
WIGGLER WORM
The red wiggler worm (Eisenia foetida, also called the redworm or manure worm) is
the worm of choice to augment the biological robustness of your moldering privy. It
is known throughout the country for the best attributes and habits for consuming
organic waste.
For many years, people have kept worm bins in their homes to compost kitchen and
other food waste year-round. Red wigglers are readily available by mail order from
firms that supply gardeners and bait shops, and once you have worms, you can easily
raise as many as you need. Red wigglers reproduce quickly, and have a voracious
appetite. Their castings (their own waste product) are a nutrient-rich, humus-like
substance sought after by gardeners. The worms are excellent burrowers, and when
introduced into the moldering privy, they help delivery of oxygen to aerobic bacteria by tunneling and churning the waste pile. Other worm species also can be beneficial, and local worms may infiltrate your moldering privy spontaneously, but based
on its experience, GMC recommends introducing the red wiggler because it is so
effective.
8: THE MOLDERING PRIVY—53
Note: red wiggler worms as an exotic species—Check with your ATC Regional Office and your local land managing agency to learn whether redworms are considered an exotic species that cannot be introduced. In the Great Smoky Mountains National Park, for example, the National Park Service considers redworms
an introduced species, so moldering privies can not use them. Fortunately, the
moldering privy relies on many indigenous organisms to break down waste, and
the worms are an enhancement, not a requirement for successful operation.
8.5
The majority of the maintaining clubs along the Appalachian Trail have limited
money and manpower, and their need for an alternative system to the pit toilet is
becoming increasingly apparent. Shelter use is increasing once again, and some members of the trail management community feel we are in the midst of a second backpacking boom that could surpass the use levels seen in the 1970s.
Several kinds of composting systems can replace pit toilets, but the moldering privy
is especially useful in the backcountry.
• Batch-bin systems require a high level of oversight to function correctly. Despite
what some bumper stickers suggest, much of composting doesn’t just “happen.”
Batch bin systems require many hours of work each season by dedicated field staff
and volunteers to ensure the process succeeds. Experience has taught us that an
active presence at the site is needed weekly throughout the season. In addition,
hundreds of pounds of hardwood bark mulch must be packed in to batch-bin
system sites each season, a very arduous task.
Organizations without paid field staffs or extremely committed volunteers with
lots of time cannot meet these requirements. There may be volunteers willing to
get involved with batch bin composting, but there are generally not enough to
meet the high demands of this system.
In addition, batch-bin systems are best suited to sites with a high volume of use.
Starting a run in thermophilic (high temperature) composting requires a generous quantity of fresh waste, so it may not operate well at low- to medium-use
sites.
Batch-bin composting systems cost significantly more than pit toilets, and this
cost may be out of reach to some clubs and organizations.
• Continuous-composting systems—Commercially manufactured composting toilets
are even more expensive to install than batch-bin composting systems, although
they can be cheaper in the long run at very high-use sites because of reduced
labor requirements. Even in the long run, however, they are still substantially
more expensive than the moldering privy.
Key advantages of a moldering privy—Compared to other composting systems, the
moldering privy offers several substantial advantages:
1. Convenience—The moldering privy eliminates the need to search for new pit
sites and move the toilet frequently (sometimes a great distance).
Many clubs have found that at old backcountry sites the best places for holes
have already been used. More often than not, they are still contaminated, and
can’t be re-used. Pits can be contaminated and unpleasant for three to five years—
or more—after being closed. Locating a new pit far enough away from the water
COMPARISON OF
THE MOLDERING PRIVY
WITH OTHER
COMPOSTING TOILETS
54—APPALACHIAN TRAIL CONFERENCE —BACKCOUNTRY SANITATION MANUAL
source, yet not too far away from the facility to discourage use, is a big challenge.
The moldering privy solves this problem. The toilet can remain at the best site
indefinitely. With a moldering privy, you can create a permanent spot for sanitation management, independent of soil depth.
2. Reduced pollution—The moldering privy reduces the likelihood of water pollution and groundwater contamination.
Many backcountry privies are in areas with seasonal high water tables, and consequently will have their pits filled with water for a third of the year, or more.
That results in anaerobic conditions (which favor the propagation of human
pathogens) and groundwater contamination that can be a threat to public health.
The moldering privy sits on top of the surface of the soil, and eliminates the need
for a pit altogether. The composting mass cannot become waterlogged, so any
liquid that drains through the pile is exposed to aerobic treatment before entering the soil.
3. Reduced maintenance—The moldering privy reduces labor and maintenance needs
and costs.
Once moldering privies are installed, most maintenance can be accomplished by
one volunteer visiting the site three to four times a year, although more frequent
attention may be needed at high-use sites.
The moldering privy relies more on natural processes than human manipulation
of the excrement to facilitate its breakdown. Liquid separates by gravity out of
the pile, so it requires no attention or effort.
Except where prohibited, the maintainer adds a cup of red worms to the pile
once or twice a season to speed decomposition. He or she waters the pile if it is
dry. (Adding a drop or two of liquid biodegradable detergent to the water helps
water penetrate a dry pile rather than run off the surface.) The maintainer and
users add bulking agent to improve the porosity of the pile, balance the carbon to
nitrogen ratio, and introduce organisms and funguses that will assist in the breakdown of the pile. The maintainer may keep a container full of duff or other bulking agent inside the outhouse to encourage people to deposit it on the pile.
The maintainer stirs the pile if it appears that the excrement and bulking agent
are segregated. Stirring is usually required infrequently, especially if redworms
are active (as opposed to every three or four days with other systems).
At longer intervals, the maintaining organization moves the outhouse when the
crib is full to another crib. Four people can easily move an outhouse from one
freestanding crib to another; one person can do the job with some multichamber
crib designs. Moves are seldom needed, except at high-use sites.
See Section 9—”Batch-Bin Composting,” for detailed information on
spreading compost.
When waste is fully composted, the maintainer spreads it on the forest floor or
buries it in a secluded area well away from water and the shelter or campsite. The
procedure is the same as for batch-bin composting systems. See Chapter 7—
Descriptions of Systems, Batch-Bin Composting, for detailed information on
spreading compost.
8: THE MOLDERING PRIVY—55
4. Reduced odor—The moldering privy reduces offensive odors.
Pit toilets are anaerobic, and anaerobic bacteria produce strong odors when they
break down waste, particularly when the waste mass is saturated with urine. Some
hikers refuse to use pit toilets because of the odor.
In contrast, the moldering privy is aerobic. It is not completely odorless, but
when working properly its odor is not strong, and the primary component of the
odor is earthy, which improves the experience of the hikers and campers. Thruhikers stopping at Little Rock Pond Shelter, the site of the GMC’s first moldering privy, regularly noted in the shelter log that the privy was the most pleasant
one they had encountered since leaving Georgia.
5. Reduced cost—The moldering privy is comparatively inexpensive.
A complete batch-bin style composting system (with or without a beyond-thebin liquid filter) can easily cost $1,000 to $5,000. The moldering privy designs
described in this chapter can be built from $200 to $500, depending on whether
pressure-treated lumber is used and whether the toilet building itself is replaced.
Manufactured composting-toilet systems, with the buildings housing them, can
cost from $10,000 to as much as $80,000. (See Chapter 8—Case Studies, Appalachian Mountain Club Clivus Multrum Composting Toilet, and Randolph Mountain Club Bio-Sun Composting Toilet.)
(See Chapter 8—Case Studies, Appalachian Mountain Club Clivus
Multrum Composting Toilet, and
Randolph Mountain Club Bio-Sun
Composting Toilet.)
8.6
The Green Mountain Club’s experience using moldering privies has generated a
good deal of interest in the technology. Here are some basic questions frequently
asked of the system’s developers:
Q: Where can I get red wiggler worms?
A: GMC buys them from Gardener’s Supply Inc. of South Burlington, Vermont
(800) 863-1700; <www.gardeners.com>.
As of March 2001, the worms (Item #02-232) were selling at $29.95 for two
pounds. If you are a non-profit Trail club, you may be able to get a discount. The
worms are shipped via UPS. When you receive your worms, transfer them to a
bin and give them food. Gardener’s Supply recommends giving them melons, but
they will consume any vegetable garbage.
If you do it right, you should only have to purchase worms once. If you provide
enough food and the right environment, the worms will reproduce and give you
an annual harvest.
GMC’s goal is to maintain a supply of worms at our headquarters to be dispersed
to various moldering privy sites along the Long Trail/Appalachian Trail. Given
the size of our trail system, we may seek volunteers to host regional worm farms
to reduce travel expenses.
Q: How do I care for and maintain my supply of worms?
A: We created two worm bins made of five-gallon food-grade plastic buckets with
lids. Buckets were available free or inexpensively from restaurants such as Dunkin
FREQUENTLY ASKED
QUESTIONS ABOUT RED
WIGGLER WORMS AND
MOLDERING PRIVIES
56—APPALACHIAN TRAIL CONFERENCE —BACKCOUNTRY SANITATION MANUAL
Donuts, or from some hardware stores. We drilled holes in the lids for air, and in
the bottoms for drainage (without drainage, worms will drown). Other people
who raise worms prefer shallower containers than five-gallon buckets, but the
buckets have worked for us.
We lined the bottoms of the buckets with shredded newspaper, and filled the
buckets two-thirds full of garden soil. Commercial potting soil or other bedding
materials may be preferable if your local soil tends to compact excessively.
For more information on raising
redworms, consult Worms Eat My
Garbage by Mary Appelhof, 1982,
Flower Press, 10332 Shaver Road,
Kalamazoo MI 49002.
We feed the worms food waste, placing it on the surface of the soil. Be careful not
to supply too much food waste with high water content (many fruits and vegetables) at once. Water can accumulate faster than it can drain, and the worms
will drown.
For more information on raising redworms, consult Worms Eat My Garbage by
Mary Appelhof, 1982, Flower Press, 10332 Shaver Road, Kalamazoo MI 49002.
Q: How many worms do I need to put in a moldering privy, and how often?
A: We have not counted worms; you don’t need to, either. Worms tend to cluster in
balls in the worm bin. Each moldering privy should get a ball of worms about the
size of a baseball. This ball of worms conveniently fits into an eight-ounce yogurt
cup, which is an ideal container for transporting worms into a backcountry site,
as long as transportation is quick.
You should only have to introduce worms once a season, in early spring when the
pile has thawed out, unless the population dies. At low-elevation sites, moles,
voles, mice and other predators may eat some or all of your worms. This may be
prevented by lining the bottom of the crib with hardware cloth. Since the
composting environment is corrosive, the hardware cloth may need replacement
when finished compost is removed from the crib.
Q: If the bottom of the moldering privy is open to the soil, won’t the worms leave?
A: Only if conditions in the pile become unfavorable. The waste pile in the toilet
will probably be the best habitat for worms in the area of the toilet. This should
entice them—as well as attract other local desirable organisms—to stay,.
Q: Will the worms survive over the winter in the field?
A: Probably not. In a cold climate, the waste mass will probably freeze all the way
through. Unless there is enough soil so the worms can burrow below the frost
line, they will die. Unless you see active worms in the spring, you should introduce worms each year.
Q: Can hikers and campers put food waste into the moldering privy?
A: They could, but this would take up valuable space and attract flies and other
pests (including big ones like raccoons and bears) to the privy. Stewardship signs
should instruct users to deposit nothing but human waste and toilet paper in a
moldering privy.
Q: What else do I need to know about keeping worms alive and working in a privy?
A: Redworms are fairly self-sufficient creatures. The key to their survival is a favorable environment. Moisture in the pile and aeration provided by forest duff or
other bulking agents must be monitored regularly. Since it is protected from rain
8: THE MOLDERING PRIVY—57
by an outhouse, parts or all of the pile may dry too much, especially if air can
blow freely through the privy crib or the privy is in the sun, so occasional light
watering is helpful. Adding a drop or two of liquid biodegradable detergent will
help water penetrate a dry pile rather than run off the surface.
If you keep the compost pile conditions favorable, the worms will thrive and
increase their level of consumption of waste, reducing the need to service the
unit as often.
8.7
Primary Components—The GMC moldering privy system has two components:
1. Moldering crib—The crib, made from dimensional lumber or landscaping timbers, creates the above-ground chamber where waste is stored and composted.
The toilet shelter, or outhouse, sits on top of the crib. The crib confines the
waste pile while allowing air and digesting organisms in and letting liquid drain
out.
COMPONENTS OF THE
GMC MOLDERING PRIVY
SYSTEM
GMC’s crib is 48 inches long by 48 inches wide by 30 inches deep. That provides
40 cubic feet, which is a lot of storage space. Two cribs, or more if use levels
dictate, are constructed. They may be either freestanding cribs, or a unit with
two or more chambers along which the outhouse can be slid.
After the first crib is full, the outhouse is moved onto the second crib. Each
season, red wiggler worms are introduced into the pile by maintainers to speed
decomposition. While the second crib is being filled, the first crib is capped—
that is, covered with a layer of hay or similar material, followed by a protective
cage attached to the top of the crib to prevent tampering. Thus covered, it continues to compost until the second crib is full.
The time required to fill the second crib ensures waste is fully composted, as long
as it is more than a year. If cribs fill in less than a year, more than two cribs are
needed. The operator can enhance the composting process in filled cribs by turning piles with a spading fork periodically, adding additional carbon-based bulking agents like wood shavings, and continuing to introduce red worms each spring.
The outhouse is returned to the first crib after its composted material has been
spread on the forest floor or given a shallow burial in a dry, unfrequented spot.
2. Outhouse—GMC uses a lightweight outhouse, or privy shelter, with a 3-by-4 foot floor to make it easier to move it, both to the backcountry site and from crib
to crib.
8.8
Different regions of the Trail present different challenges for obtaining materials to
use in construction of moldering privies. The Green Mountain Club used the following sources:
1. Moldering crib—GMC bought cribbing material at a local lumberyard. We made
our first moldering crib of 6-by-6-inch untreated cedar landscaping timbers, which
were light to carry and easy to work with. Later we decided that a pressure-treated
crib would last longer and reduce maintenance costs. However, the cedar crib
has shown no signs of deterioration in three years.
SOURCES OF MATERIALS
58—APPALACHIAN TRAIL CONFERENCE —BACKCOUNTRY SANITATION MANUAL
2. Outhouse—GMC has bought lumber for outhouses at local lumber yards in Vermont. Our outhouses are not built of pressure-treated (PT) wood. That was the
choice of the volunteers who built them. Using PT lumber for the floor and
lower parts of the outhouse would lengthen its life and might save money in the
long run, despite its greater cost.
3. Stewardship signs—An excellent waterproof and tear-resistant plastic paper, with
the trade name of NeverTear, made by Xerox, was employed at GMC sites. This
or similar products should be available at your local office supply store, or the
store can order it from Xerox. Paper signs created on a personal computer can be
photocopied onto NeverTear, which also can be photocopied.
4. Miscellaneous components—GMC bought screening, hardware cloth, poultry
staples, galvanized spikes, angle brackets, door handles, hooks and eyes, toilet
seats, flashing, roofing, drill bits etc. at a local hardware store. Be sure to tell the
store if your organization is tax-exempt.
8.9
CONSTRUCTION
SPECIFICATIONS
Our current design of moldering privy cribs units is 4 feet square, with vertical sides.
The crib is built of 6-inch-by-6-inch dimensional pressure-treated timbers, except
some parts of the lowest course, which are 4-by-6-inch PT lumber. The finished
height of the crib is about 30 inches. The inside dimension is about 3 feet square (4
feet minus the width of two 6-inch timbers).
The outhouse set atop the crib is 3 feet wide by 4 feet deep, and therefore spans the
whole depth of the crib front to back. The base of the outhouse typically overlaps
the sides of the crib by an inch or so, but the primary support of the outhouse is the
front and rear of the crib. The top course of timbers is adjustable, so the crib can be
used with existing outhouses of varying dimensions. Gaps can be covered by PT
plywood if necessary.
If the size of the top course of timbers is varied to fit an outhouse with smaller
dimensions by trimming some of its parts, this will affect the pilot hole layout described below. For a larger outhouse, it is best to build a larger crib. However, we
recommend against larger cribs and outhouses because the components are difficult
to transport to backcountry sites. For simplicity, our standard square crib is described.
The jury is still out on the effects PT lumber on soil, which might absorb toxic
compounds from treated wood. Biologically healthy soil absorbs liquid from a moldering privy and provides backup treatment if necessary, so PT lumber might provide
durability and long-term economy at the expense of effective waste treatment.
GMC has built experimental cribs entirely of untreated hemlock; of a bottom course
of PT lumber with a hemlock top; and entirely of PT lumber, to investigate the
factors of toxicity, longevity and cost. We will observe these cribs closely for differences in the apparent effectiveness of the biological community in consuming waste,
factoring out other variables such as use levels and climate as well as we can. We
may also test soils for residues from PT lumber.
If untreated cribbing lasts long enough, it would be a viable option for clubs with
limited financial resources. For example, if the hemlock crib lasts for fifteen years,
replacement of both the crib and the toilet could be done at the same time, allowing
for one-time fund acquisition at each replacement cycle.
8: THE MOLDERING PRIVY—59
8.10
GMC employed the following steps in advance of final construction of the privy:
1. Cutting the cribbing—Untreated green hemlock was rough cut a full 6 inches square,
weighing about 11 pounds per linear foot. The stock pieces ran between 12 and
13 feet long and were generally clear of knots, wane and twist.
The “6-by-6” (actually 51⁄2-inch square) or “4-by-6” (actually 31⁄2-inch by 51⁄2inch) PT lumber was 0.40 CCA treated for full ground contact, and varied greatly
in weight depending on its storage conditions. After storage outside it can weigh
twice as much as green hemlock. The lighter the material, the better, so we recommend covered storage. Both eight-foot and twelve-foot stock were used as
available. This material rarely had as much as 1⁄4 inch overage in length.
The stock was laid out on blocking on the ground for cutting. For some of the
hemlock material it was necessary to scribe and cut an end square before laying
out the other pieces to be cut from the timber. The PT material was always square.
The stock was cut freehand with a chain saw, and was scribed on two adjoining
sides to give the sawyer both a square line and a plumb line to follow. The chain
saw was a fairly rough cutting tool, having a 3⁄8-inch kerf, but cribbing pieces
were generally within 1⁄2 inch to 3⁄4 inch of the desired length. If greater precision
is desired, a skilled person with a sharp bow saw can cut to much closer tolerances without spending much more time.
The PT 4-by-6-inch stock, as well as other miscellaneous pieces (stair treads,
cleats) were cut with a 12-inch miter saw when available. This produced very
square ends, which helped assure a square shape for the base of the crib during
assembly.
2. Pilot holes for spiking—Two systems were used to fasten the cribbing. In the early
designs, every course of cribbing material was nailed to the course below using
10-inch galvanized spikes. In later designs, the corners of the crib were pinned in
place atop each other using concrete reinforcing bar (rebar) set in pre-drilled
holes. The second system was much faster to assemble in the field, but it required
some additional drilling and more careful layout ahead of time. The rebar method
of fastening cannot be used with a crib that is wider at the base than at the top,
which is a major advantage of cribs with vertical sides.
In both systems, the base square is made of two 4-foot-long “6-by-6” pieces and
two 3-foot-long “4-by-6” pieces. Those must be spiked together to provide a stable,
rigid, bottom course. In addition, the two shorter members of the top course (36
inches long) are spiked to the course below to hold them in place. It is always
necessary to drill pilot holes for spikes to avoid splitting the lumber! We also countersank
the spikes about 1 inch for more equal penetration of the two pieces.
Pilot holes for spikes were always centered on cribbing pieces. The countersink
for the spike head was first drilled using a 7⁄8-inch spade bit, to a depth of about
one inch. A 12-by-5⁄16-inch twist shank bit was then used to finish the pilot hole
through the piece.
• NOTE 1: Only the countersink and pilot of one member were drilled in advance. The corresponding 5⁄16-inch pilot on the second member was drilled in
the field at the time of assembly.
• NOTE 2: The 3⁄8-inch spike shank was 1⁄16 inch larger than the 5⁄16-inch pilot.
ADVANCE PREPARATION
60—APPALACHIAN TRAIL CONFERENCE —BACKCOUNTRY SANITATION MANUAL
• NOTE 3: If the entire crib is to be spiked together, pilot holes in successive
courses must be offset so that the spikes in upper courses will not hit the spikes
in the course below.
3. Pilot holes for rebar supports—The rebar system requires that holes be drilled through
both ends of each 4-foot piece of cribbing. These holes must align well enough
that the pieces of cribbing may be dropped on top of the standing rebar without
bending or binding. Half-inch rebar was used, and 3⁄4-inch holes were drilled.
The 1⁄4-inch overage accommodated some misalignment during assembly, but the
finished product locked together very tightly.
Lay out holes as follows: Measure 3 inches in from one end of the timber, and
draw a square line. Mark the center of the timber on this line. This will be the
location of the first hole. If all the timbers were exactly 48 inches long, you could
simply repeat the process at the other end of the same timber, and the distance
between the holes would always be 42 inches. However, it is essential to keep the
distance between the holes the same, despite variations in the length of the timbers as large as 3⁄4 inch. Therefore, measure 42 inches from the center of the first
hole (or 45 inches from that end of the timber) and make another square line.
Find the center point of the timber on that line, and it will be the location of the
second hole. Drill pilot holes for rebar with a 3⁄4-inch spade bit, lengthened if
necessary with a 6-inch hex-keyed extension so it will drill all the way through
the timber. A 1⁄2-inch chuck electric drill speeds the process. Be sure to drill holes
square to the top and bottom surfaces of the timber. Block timbers so the drill bit
will not hit dirt or rocks.
When drilling rebar pilot holes it is useful to pre-assemble the crib. Begin by
laying out the bottom pieces: two four-foot “6-by-6” pieces and two three-foot
“4-by-6” pieces in a tight square. Note that the four-foot pieces will require horizontal countersinks and pilot holes for spikes (into the three-foot pieces) as well
as vertical rebar pilot holes. Once these two four-foot pieces are prepared, mark
them clearly, because they will be required early in the construction process.
Continue the pre-assembly by reforming the base square and setting up the rebar.
Carefully fit successive courses of four-foot timbers on top of the base. Note that
the next four courses of cribbing (eight pieces total) are all the same in forming a
square crib with vertical sides.
• NOTE: If the topmost course is to be square with the other courses, no modification is necessary. However, if the top course is to be stepped-in to accommodate the outhouse, modification of the pilot hole measurements in the two
topmost timbers will be required.
4. Cutting the rebar—Cut four pieces of half-inch rebar 30 inches long, using a hacksaw.
Tools used in the workshop—The following tools were used off-site to prepare the
material for field assembly:
•
•
•
•
•
•
•
Chain saw
Speed square
Tin snips (for cutting hardware cloth)
Cordless drill and standard A.C. electric drill
12" Miter saw (standard A.C.)
Cordless circular saw
Hacksaw
8: THE MOLDERING PRIVY—61
8.11
Field assembly of prepared materials consists of finding a site for the unit, assembling the crib, providing screening, attaching the stairs, attaching the outhouse,
and completing the finishing touches.
1. Siting the unit—Locate a spot with a reasonable balance of the following factors:
Topography: A level spot is important. The moldering privy allows urine to drain
into the soil below the crib, where it will be cleansed by the biologically active
layer of the soil (the top six inches). Too much slope could cause urine to stream
on the surface, which is unappealing and a potential health hazard. However,
avoid places vulnerable to flooding.
Water table: If possible, dig test pits to determine the seasonal high water table at
spots you are considering. Soil below the seasonal high water table usually has a
tell-tale mottled appearance. Pick a spot with as much soil above the seasonal
high water table as possible.
Sun and shade: Keeping the privy shaded in summer will increase the productivity of the worms and other soil creatures who prefer a dark, moist environment.
(Banking duff, hay or straw against the outside of the crib can also help maintain
the optimum temperature and moisture.) If possible, site the privy under deciduous trees so it is shaded during the summer and sunlit in winter, which will help
prolong the life of the structure by melting snow and keeping it dry. Winter sun
exposure also helps keep snow from blocking the door.
Water sources: Make every effort to stay at least 200 feet from all water and downhill from where hikers will collect drinking water.
Aesthetics: If possible, place the privy far enough away from the camp site to
protect the camping experience, but not so far that people will not use it. This
requires judgment, and possibly observation of camper and hiker behavior. The
optimum distance is affected by things such as slope and footing of the approach
trail (people often do not wear boots at night, so the approach trail should be
relatively easy). Separation from the campsite also helps discourage winter vandals from considering it an easy source of firewood (this is no joke).
Prevailing winds: Try to locate where wind will usually carry odor away from the shelter and tenting areas. Locate away from areas prone to drifting snow in winter.
Privacy: Take advantage of trees or other forms of shielding from the shelter or
tent site, but provide directional sign(s) to the privy and a map inside the shelter.
Face the outhouse door away from shelter opening and trails, unless the location
is well shielded.
Logistics: Try pick a place near a source of leaves and duff.
2. Assembling the crib—The process in the field is simple once materials are on
site and sorted.
Begin by locating the bottom course pieces. Stand the “4-by-6” pieces on end,
and set a piloted “6-by-6” member atop them. Holding the assembly square, finish the spike pilot hole into the three-foot timber using the 5⁄16-inch drill bit,
then spike this corner. Repeat the process for the other three corners. Check the
assembled base for squareness by ensuring both diagonal corner-to-corner measurements are identical. Set the squared base onto the prepared site, check it
FIELD ASSEMBLY
62—APPALACHIAN TRAIL CONFERENCE —BACKCOUNTRY SANITATION MANUAL
again, insert the rebar, and add the remaining courses of four-foot timbers. Repeat the piloting and spiking process for the short pieces in the top course.
Remove a couple of inches of soil from the bottom of the crib, to create a depression to retain liquid long enough for it to seep into the soil. Pile this soil around
the outside of the bottom of the crib.
If you plan to introduce redworms and you wish to prevent predation by mice,
voles, and the like (a problem more likely at lower elevations), line the bottom
of the depression with hardware cloth.
3. Screening—The inside of the crib is lined with 1⁄2-inch mesh hardware cloth,
secured with 3⁄4-inch poultry staples. The hardware cloth may be cut into eightinch strips, which will cover the openings between timbers and use less material.
The outside of the crib is covered with both the half-inch hardware cloth and
dark-colored fly screening. The dark color helps shade the pile, keeping worms
and other organisms active.
4. Attaching the stairs—Stairs to the outhouse are made of commercial three-step
pressure-treated stringers, and treads of either 2-by-8-inch or 2-by-10 inch PT
lumber, 28 inches to 32 inches wide, depending on availability. Secure stringers
and treads with 2.5-inch galvanized deck screws. Screws are better than nails,
because they permit disassembly and attachment to another crib later. Support
the stringers with a 2-by-4-inch pressure-treated cleat, or galvanized joist hangers or framing anchors. It may be necessary to enlarge holes to accommodate
screws if the hardware was designed for nails.
5. Attaching the outhouse—Use galvanized angle brackets or framing anchors to
fasten the outhouse to the top course of timbers. Use galvanized screws (lag screws
or deck screws work well) to facilitate future removal. Again, it may be necessary
to enlarge holes to accommodate screws if the hardware was designed for nails.
6. Finishing touches—A tube of aluminum flashing attached to the underside of
the toilet seat acts as a splash guard and ensures the waste does not get caught on
the cribbing or screen.
A stewardship sign on the inside and outside of the door should explain the
system to the user and provide instructions. Maintainers may also want to keep a
small can, waste basket, or bucket inside the privy filled with duff or other bulking agent, and encourage hikers to keep it filled.
Tools used in the field—The following tools were used on-site to for field assembly:
• Cordless drill
• Drill bits:
Spade bits:
3
⁄4" (nail head countersinks)
3
⁄4" (rebar holes)
Standard twist shank drill bit:
5
⁄16" x 10" (nail shank)
• Two-pound hand sledge
• Hammer
• Shovel
• Tape measure
• Level
• Weatherproof paper (for the outhouse stewardship signs)
• Staple gun (to attach screen and hardware cloth into place before nailing with
poultry staples; also used to post outhouse stewardship sign)
9
Batch-Bin Composting
Pete Ketcham, Field Supervisor, Green Mountain Club
9.1
The batch-bin system was introduced to the Green Mountains of Vermont and the
White Mountains of New Hampshire as a pilot project in waste management in the
mid 1970s. The design and prototype were created by Ray Leonard of the U.S. Forest Service’s Backcountry Research Project at the Northeastern Forest Experiment
Station in Durham, New Hampshire.
The system was designed to provide forest, park and trail managers with a method
for human-waste management at remote recreation sites, generally high in the mountains. Thin and frequently saturated soils at many of these sites are unsuitable for pit
toilets, which release untreated wastes that leach into groundwater. Disease-causing
organisms, called pathogens, can travel up to five feet in fine, sandy soil and as far as
200 feet in soil of coarser fragments (McGauhey and Krone 1967)—even farther if
the soil is very moist. The batch-bin system permits on-site disposal of human waste
after safe decomposition in a leakproof container.
Since their introduction, batch-bin composting systems have evolved somewhat
differently in the Green Mountains and White Mountains, although the techniques
are similar in both places and the results are the same.
The Green Mountain Club (GMC) system uses one large composting bin, and employs storage containers to accumulate enough waste to fill the bin. The Appalachian Mountain Club (AMC) system uses two smaller composting bins in sequence,
and it uses no storage containers to accumulate sewage before a composting run
starts. The GMC system uses a wooden drying rack to dry and age compost before
sifting it through a screen, whereas the AMC system in the White Mountains dries
compost right on a sifting screen. All AMC systems also incorporate beyond-thebin liquid separation, which keeps the mixture of sewage and bark mulch comparatively dry and reduces its volume.
The following text describes the GMC system, and notes points at which it differs
from the AMC system.
BACKGROUND
64—APPALACHIAN TRAIL CONFERENCE —BACKCOUNTRY SANITATION MANUAL
Figure 9.1—Diagram of Green Mountain Club batch-bin composting toilet systems
depicting all of the system’s components. Note that the outhouse design depicted is
only one of several options. Not shown are the two 32-gallon storage cans the Green
Mountain Club uses as part of their system. The Appalachian Mountain Club uses two
150-gallon stainless steel composting bins instead of storage cans.” Diagram from the
Green Mountain Club.
9.2
HOW THE BATCH-BIN
COMPOSTING SYSTEM
WORKS
How it functions—The batch-bin system functions as follows:
1. Wastes accumulate in a 70-gallon Rubbermaid or similar polyethylene leakproof
container, called a “catcher,” under the seat of a conventional outhouse with a
modified bench. In the GMC system, the catcher is periodically emptied into
one of two 32-gallon rectangular garbage containers for storage. In the AMC
system, a compost run is started when the catcher is full.
Each time people use the toilet, they add a handful of ground hardwood bark
mulch (available from lumber mill debarking operations). Hardwood bark has
the best carbon-to-nitrogen ratio and structural shape for composting. Other organic materials, such as peat moss, work, but poorly.
2. When both storage containers and the catcher are full, all of the sewage and bark
mixture is transferred to a composting bin of 160 to 210 gallons. In Vermont,
GMC uses a cylindrical 210-gallon plastic composting bin originally designed for
aquaculture. It weighs about 45 pounds, and is four feet in diameter and 2.5 feet
high. It costs about $175. The custom-fabricated lid costs about $135.
In the White Mountains in New Hampshire, the Appalachian Mountain Club
uses a custom-made rectangular stainless steel composting bin of 150 gallons.
The bin weighs 150 pounds empty. It is three feet high at the back, two feet high
at the front, four feet long and three feet wide. It costs about $1,000.
3. The wastes are thoroughly mixed with enough additional hardwood bark, and
recycled compost if available, to soak up excess liquid. The material is completely
9: BATCH-BIN COMPOSTING—65
mixed, broken up and aerated with a turning fork, and the bin is almost full. This
results in a carbon-to-nitrogen ratio of approximately 30:1 by weight, which is
optimum for the composting process.
4. Now a “compost run” begins. During the run, no new wastes are added to the
compost bin, and the pile is turned every four to five days. Waste breakdown
occurs as local soil bacteria and fungi proliferate in the compost. Human pathogen destruction results from temperatures higher than 90 degrees F. (32 degrees
C.) competition with hardy local microorganisms, and from processes such as
oxidation and antibiosis, intrinsic to rapid aerobic decomposition (for more details, see Chapter 3—The Decomposition Process).
A GMC run lasts four to six weeks, depending on ambient temperatures and
operator skill and energy. The compost then goes to a storage platform, or drying
rack, to further decompose and dry for six months to a year. An AMC run lasts
two to four weeks in each composting bin (four to eight weeks total), and then
the compost is put on a screen for drying, aeration and sifting.
5. After the material has sufficiently aged and dried, the mixture of humus and bark
is sifted to capture bark chips that can be reused in the next run. Screening also
catches any chunks of material that escaped decomposition. These can be broken up and placed in the next run. The screen is a five-by-four-foot wooden
frame on legs three or four feet off the ground. The best screening material is
heavy gauge diamond patterned expanded sheet steel. However, a double layer of
1
⁄4-inch hardware cloth also works.
6. Finally, some of the finished compost is recycled into the next run, which helps
inoculate the run with beneficial organisms. The rest is scattered thinly over
selected spreading sites, or buried if necessary to satisfy regulations.
Figure 9.2—Diagram depicting the Green Mountain Club batch-bin compost system
bin and lid. The lid is constructed of dimensional lumber. The Green Mountain Club
recommends using manufactured plastic lids whenever possible because they have a
longer life expectancy in the field and are less likely to leak. If cost is a factor, a wooden
lid may be the best option. Diagram from the Green Mountain Club.”
For more details, see Section 3—
“The Decomposition Process.”
66—APPALACHIAN TRAIL CONFERENCE —BACKCOUNTRY SANITATION MANUAL
9.3
COMPONENTS OF THE
BATCH-BIN COMPOSTING
SYSTEM
Operator—The operator of the batch-bin composting system is its most important
element. Mastery of the process requires resourcefulness. The operator must maintain an optimal aerobic environment for composting, which requires sensitivity to
the variables inherent in a biological waste management system, and he or she must
be prepared to deal with unforeseen difficulties.
Operating a compost pile is a continuous experiment. Try different handling procedures to see which are the most effective in the conditions where you work. Turn
the compost pile with co-workers to ease the burden and share insights. Refer to the
manual as you go. Keep accurate records so the next operator will know what to
expect.
Above all, keep a level head. No problem is insurmountable if you are patient,
thoughtful and inventive.
Outhouse—The batch-bin system uses an conventional outhouse, with the design
modified to accommodate a 70-gallon catcher under the seat. The rear has a hinged
door for removing the catcher, and the outhouse needs a solid platform extending
far enough behind it to slide the catcher out easily. An existing outhouse can be
used if it can be properly modified.
Regulations may require screened vent stacks in some areas; otherwise, they can be
omitted. Screened vent stacks normally do nothing useful in a backcountry privy,
Figure 9.3—This diagram shows how to construct a chamber to house a 70-gallon
sewage catcher in either a batch-bin or beyond-the-bin system. This plan is particularly useful for converting an existing outhouse. However, a new outhouse can accommodate a 70-gallon catcher without an elevated foundation requiring a ramp or stairs.”
Plans from Paul Cunha and the Appalachian Mountain Club Trails Department.
9: BATCH-BIN COMPOSTING—67
since there is nothing to create a draft from the catcher or pit. They have been
installed habitually because of a tradition begun in the days of urban anaerobic
cesspool-style privies that produced high levels of dangerous methane. Methane is
much lighter than air, so it readily rises up a vent stack and dissipates. Backcountry
privies produce negligible amounts of methane. So the vent stacks we are accustomed to seeing on backcountry privies are ineffective and superfluous.
If you are building a new outhouse, plan it with a solid wooden floor and a platform
extending behind the rear access door far enough to allow the catcher to slide all
the way out of the outhouse. This makes moving and working with the catcher
much easier. If an existing outhouse does not have a sturdy platform, it can be firmly
secured to one.
If the distance from the underside of the privy bench to the top of the catcher is
more than six inches, attach a short piece of metal flashing to the underside of the
bench to guide waste into the catcher. This prevents waste from running down the
inside of the front wall.
Winter access and maintenance are easier if the outhouse is elevated, so its front
door and rear access door are off the ground and the catcher can be emptied if need
be without interference from deep snow. In the White Mountains, operators make a
point of composting as early and as late in the season as possible, and 70-gallon
catchers have not required emptying during the winter. GMC also has found that
70-gallon catchers will not require emptying in the winter, as long as they are emptied before winter starts.
The outhouse should be kept clean and attractive, so visitors will use it rather than
the woods. Keep a broom for sweeping the outhouse, and cleaning supplies for its
seat. A small can of paint or stain is useful for covering graffiti as fast as it appears.
Graffiti begets more graffiti.
Catcher—In the past, 20-gallon heavy plastic cans were used as catchers at most
GMC sites. However, 20-gallon catchers fill too fast at the heavily used backcountry
campsites that need batch-bin composting, particularly in winter and by large groups.
Twenty-gallon catchers often overflow during the winter and leave a mess for shelter maintainers in the spring. So AMC and GMC now use 70-gallon high density
polyethylene (HDPE) tubs, and we recommend them, especially for any site receiving off-season use.
A 70-gallon catcher weighs more than 550 pounds when full, so it must be set on
rails or on a platform extending at least five feet behind the outhouse so the operator can pull it all the way out without help.
The catcher should be low and wide rather than tall and narrow, because it is hard
to shovel out a tall container and keep the shovel handle clean. The 70-gallon
Rubbermaid stock tank used by AMC and GMC is 40.5 inches long by 32 inches
wide by 24 inches high.
Industrial-grade HDPE is corrosion proof and durable. Rubbermaid stock tanks have
built-drain plugs, which make it easy to attach a beyond-the-bin (BTB) liquid management system (See the Beyond-the-Bin section of this chapter for a diagram of
the catcher with strainer plate attachment.) If not broken, plastic will last 10 years
or more. Twisting and lifting often breaks thin plastic containers, and they tend to
crack in cold weather, so it is best to avoid inexpensive polyvinyl chloride (PVC)
garbage cans or any plastic other than HDPE. (See the Appendix for Sources of
Material and Equipment.)
See Section 10 for a diagram of the
catcher with strainer plate attachment.
See Appendix G, for “Sources of
Material and Equipment.”
68—APPALACHIAN TRAIL CONFERENCE —BACKCOUNTRY SANITATION MANUAL
Most metal containers are poor choices. Stainless steel is good, but expensive. Catchers
of other metals should be completely coated with roofing cement or some other durable
coating. However, even a coated metal catcher will last only two to three years. Metal
catchers with rounded bottoms are better than catchers with seams. Mixing wastes in
metal catchers or storage containers other than stainless steel is not recommended, because scraping will remove the coatings and accelerate corrosion.
In Great Smoky Mountains National Park, the Appalachian Trail Conference and
local trail clubs have tried using plastic garden wheelbarrows as catchers in privies.
This makes it easier to transport waste to storage containers. But the wheelbarrows
don’t hold much, so they must be emptied frequently, and they can overflow in
winter or if subjected to large groups. Liquid tends to slosh out when the shallow
wheelbarrows are moved. If liquid is to be drained for separate disposal, it must be
filtered, because the urine is contaminated from being in contact with fecal matter.
Wheelbarrows would be most effective at low-use sites visited often by a adopters or
other attendants.
A catcher larger than 70 gallons is too heavy for one person to slide out of the
outhouse. It also may allow more sewage to accumulate than the compost bin can
accommodate. In addition, the catcher may sit in the outhouse so long that it causes
problems with flies and odors in the summer. Adding fresh and recycled bark, knocking over the “cone” of bark and feces, and keeping fresh feces covered with a thin
layer of bark helps reduce flies and odors. However, there is no substitute for the
routine transfer of waste from the catcher to a storage container (in the GMC system) or the first composting bin (in the AMC system) when necessary.
Emptying catchers—If a site has received high off-season use, the pile in the collection container may be mounded into a cone. It may be necessary to push the pile
down before sliding the container out, using a stick through the privy seat. Wash
the privy seat well if it becomes contaminated. It is best to design the privy with a
flip-up bench seat to provide more sanitary access to the catcher. It is also good to
provide a rear door high enough so the catcher can be slid out of the outhouse to
manipulate its contents.
Once waste is in a storage container, do not add bark or turn it. The waste should
remain inert until you are ready to compost it.
Once most of the sewage has been shoveled out of the catcher, you may want to
dump the rest of the sewage and liquid into the storage container. But if sewage is
poured from the catcher to the storage container, it may splatter, especially if urine
has not been separated from feces. To reduce the chance of getting splashed, stand
behind the collection container. Rest the edge of the catcher gently on the storage
container. Pour carefully.
To help keep flies down, clean the catcher with several shovels full of fresh bark
before replacing it in the outhouse. Put the bark used for cleaning in the storage can
(in the GMC system) or the compost bin (in the AMC system).
Always double-check the catcher position after replacing it in the outhouse. Position the container as far forward as possible to keep urine from running over the
front edge. Line the bottom an empty catcher with three to four inches of fresh or
recycled bark mulch to help to absorb liquids and reduce odor.
Storage containers—The AMC system does not use storage containers. Wastes from
the catcher are mixed with bark a bit at a time in a mixing bin, and then placed
directly in the first composting bin. Therefore, what follows applies only to the
GMC system.
9: BATCH-BIN COMPOSTING—69
Storage containers accumulate waste for a compost run, and provide storage for fresh
waste during a run. They should be close to the outhouse, to ease transfer of waste and
minimize spillage. Set storage containers on a level, secure dry base, such as short boards.
Stay away from sharp stones, which can puncture the bottoms. Avoid rolling the storage
container on an edge, which can cause the plastic to split. It is best to leave the storage
container in one place, adjacent to the outhouse and compost bin.
Sometimes people or animals investigate or knock over storage containers. In the
Smoky Mountains, black bears have knocked over storage containers. ATC and
local clubs have solved the problem by surrounding the composting areas with electric fences. In Vermont, GMC has had more trouble with people, who often think
the storage containers are trash containers, and open them to deposit trash. Occasionally someone will maliciously knock over a container, spilling its contents. To
counteract this, GMC has been building secure, ventilated lockers for storage containers and the bark-mulch supply.
Storage containers must be leakproof, with secure lids. The GMC uses rectangular,
32-gallon Rubbermaid HDPE garbage containers. Their square shape resists warping under weight and pressure, their lids fit tightly, and their rims resist cracking
when tipped over.
Galvanized steel garbage cans have been used extensively in the past, but they rust
quickly. Fifty-five-gallon plastic or metal drums with tightly fitted lids work, but wastes
in the bottom are difficult to remove, and the drums make the compost area look like a
hazardous waste site. The volume of waste in storage also tends to be too great.
At least two storage containers are needed to hold the mixture of sewage and bark
before and during a run. GMC has found that the contents of two 32-gallon containers plus the 70-gallon catcher, plus added bark to adjust the moisture content,
are the ideal volume of sewage for composting in a 210-gallon compost bin. We try
not to have many storage containers at the site, because this allows a backlog of
sewage to develop, and increases the risk of animals or hikers knocking over the
storage containers.
Keep storage container lids tightly secured with string or bungee cords to discourage
the casually curious or litterbugs from lifting them. Label storage containers clearly
with paint or marker: RAW SEWAGE—KEEP OUT! Check regularly for leaks, and
replace leaking containers immediately.
Before any wastes are placed in a storage container, put several inches of bark and/or
finished compost in the bottom to absorb liquid and reduce odors.
Do not mix bark mulch with sewage when transferring it to storage containers.
However, you can put a layer of bark mulch and/or recycled compost on top of
sewage to control odors. The goal is to prevent sewage from starting to compost
before the planned start of a run, so there will be a large enough mass of fresh sewage
and bark to create a good, hot run. Therefore, every effort should be made to keep
the waste in the storage containers inert. This can be done by not mixing waste
when transferring it from the catcher, not adding bark mulch, and by packing the
storage containers as full as possible to reduce availability of oxygen.
If non-biodegradable trash has been thrown into the catcher, storage container, or
compost bin and is contaminated, leave it there and let it go through the compost
run. Then allow it to weather in a protected spot before packing it out.
See Appendix G, “Sources of Material and Equipment,” for more information on storage containers.
70—APPALACHIAN TRAIL CONFERENCE —BACKCOUNTRY SANITATION MANUAL
Compost bin—The bin is the key element, and the largest one, in the composting
operation. A bin of 160 to 210 gallons is optimal to create self-insulating composting
conditions. AMC and GMC have not used insulated bins, but they may be useful in
some places.
The bin or bins should be near the outhouse and storage containers, if any, to facilitate waste transfer and minimize spillage. GMC has found that one large bin ordinarily is enough at an overnight site, especially if a beyond-the-bin system or another method separates liquid from solid waste. AMC always uses two bins, partly
because usage at its sites is typically high and partly because the bins are smaller.
Initially, bins were built of marine grade plywood, laminated inside and out with
fiberglass and resin, but industrial HDPE bins are cheaper and better. Stainless steel
is even more rugged, but also heavier and more expensive. Building a leakproof
plywood bin is difficult. In addition, fiberglass resin is a health hazard and requires
approved breathing masks. HDPE is less likely to be consumed by porcupines than
plywood coated with fiberglass, and porkies cannot damage stainless steel at all.
Persistent porkies will chew through a fiberglass coating to get to the plywood inside.
• NOTE: PORCUPINES—Because of their love of salt, porcupines can be a problem
even with HDPE bins. If they are, removal of the offending animals is the best
solution. If porcupines must be eliminated, check with your regional ATC field
office and the local land manager before taking any action. Removal of any creature may not be permitted in your area. Elimination options include live trapping or removal by hunting. If you cannot remove the porcupines and they continue to be a problem, you can enclose your composting system components inside a metal cage.
Aeration tubes once were thought necessary for composting, but they actually provide minimal aeration, and they hinder turning the compost. Do not add them to
bins. The tube holes in the bin walls are points of weakness, and the edges are ideal
places for animals to begin chewing into the bin.
The original bin design used a sliding front door, but it let water into the bins.
Modern HDPE bins are only accessed from the top.
See Appendix G, “Sources of Material and Equipment.”
Compost bin lid—Many HDPE bins are available, but few are designed for use with
lids. The GMC has located a supplier who will custom fabricate snugly fitting black
plastic lids for the 210-gallon bin. (See the Appendix, Sources of Material and Equipment.) The GMC reinforces these lids to withstand winter snow loads, and we hope
the black color will provide some solar warmth.
If you can’t get a plastic lid, you can make a wooden lid. All the AMC’s stainless
steel bins are fitted with framed plywood lids, which are covered with plastic for
waterproofing when left through the winter. A lid should be sturdy to withstand
falling branches and snow. A lid of marine-grade plywood, reinforced with slats to
prevent warping, will last many years, but is heavy to pack in and maneuver.
Two sheet-metal roofing panels, overlapped and screwed to a two-by-four lumber frame,
make a sturdy top. Crimp and nail or screw down all exposed edges. Reinforce with
diagonal bracing. Secure with rocks to prevent the wind from lifting it off.
See Appendix G, “Sources of Material and Equipment.”
Fiberglass and plastic solar panels are not recommended, because they crack easily
under snow loads, a sharp blow, or a sudden twist, and they provide only a small
amount of heat from the sun in comparison to the heat generated by microbial
growth.
9: BATCH-BIN COMPOSTING—71
Transporting the compost bin to the site—AMC has flown all of its compost
bins to its sites. HDPE compost bins weigh only 60 to 100 pounds, but they are
awkward to pack to remote sites. Since the tubs are cylindrical, they can be
rolled on easy terrain. Two to four people can carry a bin upside down or lashed
to a homemade stretcher. One person can carry a bin on a wooden packboard by
resting the rim on the top of the packboard and grabbing the sides with his or
her arms.
Positioning the compost bin—Stainless steel bins have strength enough to sit directly on leveled ground.
An HDPE compost bin may be placed directly on flat level ground; on pressure
treated two-by-six-inch boards; or on a sturdy platform of pressure-treated two-bysix-inch lumber. Note that a full bin can weigh more than 1,700 pounds.
It is convenient to put the bin on a raised platform of wood or earth, and this is
especially useful if the site is wet. Pack the ground on which the bin or wooden bin
platform will sit with mineral soil or fine stream gravel to provide a solid base. Set
the empty bin or platform on the ground and try to rock it back and forth. Then tilt
it aside to look for compressed soil indicating high spots that could weaken a bin.
Shave these down until the impression of the bin or platform on the ground is
uniform, if it will sit directly on the ground. It is better to set the corners of a platform securely on large, flat rocks.
Drying rack—The drying rack (or “screen” for the AMC process) is the third stage
in composting. On GMC’s rack, composted sewage dries for six months to a year,
and any surviving pathogens are destroyed by continued exposure to unfavorable
environmental conditions. In both systems the drying process also enables the operator to sift material to reclaim bark mulch and remove trash from it.
The drying rack gives the operator a great deal of control over composting. Uncertainty whether the compost is done—that is, whether pathogens have been reduced
to an acceptable level—is eliminated by aging the material on the rack.
The compost drying rack should be near the composting bin to make transfer easier.
The best shape for the drying rack is that of a small three-sided lean-to. (See the
Appendix, Drying Rack Plans.) For a site that does one to two runs a season, a sixby-four-foot rack is good. The rack can be made from untreated lumber, since the
compost has no liquid draining from it. Two-by-six-inch boards make a long lasting
platform deck.
Higher walls in the back of the rack increase storage capacity. The front should be
open. You can use local logs for the base, but rot-resistant or pressure treated dimensional lumber is better. Provide a sturdy roof, sloped to shed water, with ample room
beneath for air flow. Metal roofing is inexpensive, easy to pack in and install, and
lasts 25 years or more.
Do not use plastic sheeting to cover the platform: it punctures, rips, and scatters,
and it traps moisture on the surface of the compost.
Examine the deck for repair whenever the rack or a portion of the rack is emptied.
Replace rotted boards or resurface the deck if needed. When resurfacing the deck of
the rack, nail new boards directly on top of old boards, giving a double thickness.
Use only a designated and labeled or color-coded shovel (red is recommended for
potentially contaminated tools) to transfer compost to the drying rack at the end of
a run. Turn compost on the rack regularly with a designated fork to enhance further
See Appendix J, “Drying Rack
Plans.”
72—APPALACHIAN TRAIL CONFERENCE —BACKCOUNTRY SANITATION MANUAL
breakdown. Adding leaves and duff at this stage introduces additional soil invertebrates to the compost, which helps speed it toward maturity.
Sifting screen—AMC makes the base of its drying rack from a screen, so material
sifts as it dries. The screen is elevated on legs, and has a frame above it so it can be
covered by a tarp in wet weather. The tarp is removed in dry weather to speed
drying.
GMC uses a separate sifting screen before spreading finished compost in the woods.
The GMC screen is a simple wooden frame approximately five by four feet, three or
four feet off the ground, covered with a double layer of heavy gauge quarter-inch
hardware cloth or heavy gauge diamond patterned expanded sheet steel. A tarp
beneath the screen captures screened compost. Locate the sifting screen on dry,
level ground adjacent to the drying rack.
In the GMC system, compost is sifted when it has been sitting in the drying rack for
six months to a year and appears dry. Use a shovel designated for clean material (a
green handle is recommended) to place compost on the screen. In the AMC system,
compost dries quickly because it is exposed to air both above and below, and is raked
frequently. Drying and sifting are complete in two to four weeks.
Rake compost gently back and forth with an ordinary garden rake to cause the finer
compost particles to fall through the screen. Bark mulch and any chunks of uncomposted sewage that managed to make it through the system remain on the screen.
Place sewage chunks back in the composting bin with the catcher/storage container
shovel (red handle), and break them up so the sewage will be adequately composted
in the next run. Bark mulch to be recycled can be placed back into the drying rack.
This composted bark mulch has a pleasant earthy odor, and it is useful as a substitute
for fresh bark when lining the catcher after emptying it.
Screened compost is ready to be spread in the woods (See 9.x below: The Finished
Product) or recycled into the next run if room permits.
The remaining chips are thoroughly dried, and bagged with special color-coded labels to indicate they are to be recycled by the caretaker. They should not be placed
in the outhouse for users to add to waste.
Transport containers—Two five-gallon plastic buckets with handles are useful for
transporting finished compost to be spread. The buckets need not be leakproof, as
they will hold compost only. Keep them labeled and removed from the site, or trash
will magically appear in them.
Composting tools—Each of two phases of the composting process requires its own
set of tools to prevent spreading pathogens to finished compost.
Phase One: This shovel and fork are used for material in the catcher and the
storage container, for starting a run, and for transferring the material from
composting bins. Tools used in each of these steps contacts waste potentially
contaminated with a significant level of disease-causing pathogens. Therefore,
these tools should have a red handle or should be wrapped with red tape. Red is
a universal sign of danger. Ideally, these tools should be stored by hanging them
from a branch or nail on a tree exposed to the weather near the rear of the outhouse. If you have a problem with hikers using or disturbing the tools, they can
be stored in a secure locker.
9: BATCH-BIN COMPOSTING—73
Phase Two: This shovel, rake and fork are used for material in the drying rack and
the sifting screen, and for spreading finished material from the transport buckets.
This material has been through a compost run with high temperatures and/or has
sat on the drying rack or screen, so it is either lightly contaminated or free of
pathogens. These tools should have a green handle or be wrapped in green
tape;green is a universal sign of safety. These tools also should be stored by hanging them from a branch or nail on a tree near the drying rack, unless hikers tend
to use or disturb them.
To avoid contaminating the finished compost, tools must not be mixed up. If you
break a tool, suspend operations until you can replace it.
The turning fork is the flat-tined spading fork variety, as opposed to the round-tined
type. Flat tines let you pick up the waste and compost for mixing. Take care not to
puncture the containers or the bin with the points.
A long-handled shovel is very useful for mixing raw wastes, because it can more easily
chop the wastes than the turning fork. It is also used for transferring wastes from the
collection container to a storage container and from the storage container to the
bin.
An ordinary garden rake is useful for sifting finished compost.
Clean the red tools after every use by wiping them with bark or finished compost,
holding them above the compost bin. Hang them outside (handles up) if possible to
facilitate cleaning by weathering. Wipe wood handles at least once a year with boiled
linseed oil.
Bark mulch (bulking agents)—Bulking agents are materials that provide carbon,
aeration and structure to the compost pile. Hardwood bark mulch is the best bulking agent for composting human wastes in the batch-bin composter.
Fine bulking agents such as peat moss, sawdust or ground dried leaves and duff are
unsatisfactory because they compact and exclude air. Bark mulch is durable, and its
chips are the right size to break up sewage and create air channels throughout the
compost pile. The structure provided also creates good surface areas for decomposer
organisms to thrive on.
The carbon-to-nitrogen (C:N) ratio of hardwood bark varies, depending on the
type of tree and the age of the bark. Fresh hardwood bark has a C:N ratio in the
range of 100:1 to 150:1. Older, dried bark has a C:N ratio of between 150:1 to 350:1,
due to nitrogen loss. At the C:N levels in old dry bark the compost process is generally not impeded, because the bark is drier and less is needed to soak up water. In
contrast, sawdust has a C:N ratio of nearly 500:1—high enough to bring decomposition to a standstill.
Bark for composting works best when fresh from the sawmill. However, it is much
more convenient to bag and store bark in the fall to have on hand for the spring,
and to distribute bark when personnel and transportation are available. Bark stored
under cover over the winter is drier, and thus lighter to pack to compost sites.
Selecting bark at the mill requires judgment. The size of the bark chips is the most
important criterion. Look for chips at least an inch to two inches long, which break
up sewage well, but less than four inches, because longer chips are hard to turn in
the compost bin.
74—APPALACHIAN TRAIL CONFERENCE —BACKCOUNTRY SANITATION MANUAL
Also, find the conveyor carrying fresh bark from the debarker. Fresh bark is often
the lightest, because it has not sat outside soaking up water. If the pile is wet, try
digging down a few inches. You may find a drier layer beneath. If you can’t find
chips of the right size in the fresh bark, look elsewhere in the storage pile, even if
you have to take wet bark.
Often, a foot or so into the pile, the bark is vigorously decomposing. Although this
decomposing bark is fairly moist, it works very well for composting human wastes.
Use a turning fork to scoop bark into bags. Shovels work, but are difficult to push
into the bark pile. Tie the bags off with string or plastic lock-ties. Use slip knots that
can easily be untied in the field: no one wants to dig out a pocket knife in the
middle of a composting operation.
GMC has found that used coffee bags or feed bags are great for mulch. They are
durable, and allow mulch to breathe and dry. They hold 40 to 60 pounds of bark, or
about 75 pounds of damp bark, which is the maximum weight for packing into a
backcountry campsite.
Figure 9.4—An example of a simple, home-made, urine diverting device that could
have many applications with a variety of systems, both those described in this manual
and others in use on the A.T. The drain pipe could lead to a beyond-the-bin liquid
management system or a simple rock-lined dry well. State and local regulations may
dictate how the liquid is managed.” From The Composting Toilet System Book by
David Del Porto and Carol Steinfeld.
9: BATCH-BIN COMPOSTING—75
Estimating the amount of bark to supply to a site depends on the level and type of
use. Day use means more urine in the catcher if urine is not separated from solid
waste. The volume of bark needed also depends on the moisture level of the bark.
Dry bark will absorb more waste water than damp bark. Keeping an accurate record
of bark use in all phases of the operation will help you plan your bark supply in the
future.
The following table is based on varying use levels at several Green Mountain Club
sites with batch-bin composters:
VISITORS/YEAR
100
200
500
850
1,200
GALLONS
OF WASTE
15
50
100
250
400
POUNDS
OF BARK
125
300
750
850
1,600
Table 9.1—Bark Amounts at GMC Sites
As you can see, bark use and sewage quantity are not directly proportional to overnight use. Day use, bark moisture content, liquid input, and the quantity of old
compost and bark recycled back into the system affect the amount of bark needed.
Keep a supply of bark on the site under cover: in the shelter, under the outhouse or
the drying rack, or raised off the ground and covered with roofing. This allows the
bark to dry as water vapor escapes through the porous bag. If bark can not be not
stored under cover, line the feed bags with plastic garbage bags to keep the bark
from absorbing more moisture. Do not place bags of bark on plastic sheeting, which
will tend to collect moisture that will soak into the bark.
Stay several bags ahead of what you need. Leave several bags over winter at the site
for use in the spring. Hide your stored bark supply or prominently label it “Fecal
Compost Material” to prevent disturbance by visitors. See 9.4 below for information on transporting bark to the site.
Keep a container of bark in the outhouse at all times. GMC has found that at sites
with an attendant, it is best to keep a small can of mulch in the outhouse and fill it
each day. This takes less space than a feed bag, is more convenient for users (floppy
bags are awkward to empty), and encourages users to throw in the right amount of
mulch.
Post a sign instructing users to throw in a handful of bark after each use of the privy.
At high-use sites, the operator should add bark during the day if more is needed.
Thermometer—A long probe thermometer is useful for monitoring the compost
process. The AMC records the temperature in both compost bins daily at approximately the same time each day, and tracks this data during a compost run. This is
helpful, but not necessary. There are many other composting indicators a maintainer can easily detect without a thermometer. However, to guarantee maximum
pathogen reduction it is helpful to be sure temperatures are reaching the thermophilic range frequently.
Store thermometers under cover to keep water from seeping into their housings.
Recalibrate occasionally, following the manufacturer’s instructions.
76—APPALACHIAN TRAIL CONFERENCE —BACKCOUNTRY SANITATION MANUAL
Wash Station—On the first visit to the site each year, bring two one-gallon plastic
milk jugs and a pump bottle of antibacterial soap to establish the wash station for
the season.
See Sanitary Procedures, Section
4—“Health and Safety Issues,” for
a complete discussion of soap,
wash jug, and hand-washing procedures.
Punch a small hole in the side of one milk jug near the bottom. Place a small twig or
nail in the hole to stem the water leak. Tie the jug to a tree. When the cap is
loosened and the twig is removed, a small stream of water comes out, allowing hand
washing without touching the jug.
Rinse off the soap bottle after each use.
9.4
BULKING AGENT
TRANSPORT OPTIONS
One of the main challenges of operating a batch-bin or beyond-the-bin composting
system is transporting bulking agent to the site. The pros and cons of each option
are discussed below.
• Pack it in: Volunteers or seasonal field staff pack mulch to the site on packboards
or pack frames.
The main advantage of this method is low cost, if volunteers are available. Paid
seasonal staff are not an option for most clubs. Packboards cost from nothing
(old pack frames) to $300, and last a long time. Packing is the easiest system to
institute, and all sites are accessible on foot.
The main disadvantage is that it is a lot of hard work, so bark mulch at the site may
run out. Many excellent trail and shelter volunteers can not carry loads of mulch.
Even vigorous club members may refrain from volunteering to avoid the possibility of being solely responsible for supplying bark mulch.
If you depend on volunteers, and they are unable or unwilling to support your
composting system, it will fail. The GMC uses large volunteer groups (typically a
camp or college group) to pack in bark mulch. This keeps individual shelter volunteers happy, and the packers can carry lighter loads and make fewer trips.
Some clubs sled mulch during the winter, and report that it is easier and more
pleasant than backpacking. To our knowledge, A.T. clubs have not tried pack
animals, dogsleds, wheeled game transporters, canoe portage buggies, wheelbarrows, garden carts or jogging strollers. Wheeled devices, even muscle powered,
are illegal in federally designated Wilderness areas and on A.T. lands owned by
the Park Service. They may also be illegal on other classifications of federal or
state land. Check with your regional ATC office and with your land owning
agency.
• Drive It In: If you have legal road access, an ATV or a four-wheel-drive vehicle and the money to run it, getting bark to the site is easy. Snowmobiles
may be feasible in some locations. The main advantage is that it saves work,
making it easier to recruit and keep volunteers.
The main disadvantage of vehicle transport is the potential to destroy the primitive experience of the A.T. Nothing degrades a hiker’s experience more than the
arrival of a motor vehicle. In addition, regular vehicle access may encourage
drivers of ATVs or vehicles to use the route illegally. Maintaining the route and
the vehicle can be expensive, unless provided by volunteers or the land manager.
To minimize disruption, schedule vehicle visits when use of the site is lowest and
9: BATCH-BIN COMPOSTING—77
disturbance of plants and animals will be least. Be sure to contact your regional
ATC field office and the local land manager to see whether vehicle access is legal and
feasible.
• Fly It In: The easiest (and the hardest) way to get bulking agent to a site is a
helicopter. The only A.T. club to use this method is the Appalachian Mountain Club in New Hampshire. With 90,000 members, AMC is the largest A.T.
club. The club has a full time trails department staff to manage the airlift
budget and the split-second logistics required to use a helicopter efficiently.
AMC is fortunate to have the means to use a helicopter, because the exceptionally high use of their campsites and the rugged terrain of the White Mountains make it impossible to pack in enough bark even with volunteer groups
augmenting their paid seasonal staff.
The main advantage of airlifting is the ability to supply a season’s bulking agent in
one shot. If your sites have extremely high use, too little soil for a moldering
privy (which can use lightweight shavings or local forest duff), and are very hard
to reach, airlifting could be your best or even only option. A small club could
afford an airlift if it could get the use of a helicopter donated by a helicopter
company or the local National Guard.
The main disadvantage, of course, is high cost. Helicopters can cost $800 to $1000
an hour. There also may be legal restrictions. If you are considering airlifting any
materials or supplies, contact your regional ATC field office and the local land manager
to see if it will be legal and feasible.
9.5
A compost run with three thermophilic temperature cycles and six turnings takes
four to six weeks. Climate determines the maximum number of runs per year. At
mountain sites in the Northeast, the compost season runs from mid-May through
mid-September, generally 15 to 18 weeks.
Capacity—Capacity depends on the number of compost bins and the available labor, bark, and spreading areas. One 210-gallon bin can compost 130 gallons of bark
and sewage mixture per run, although skilled composter operators may be able to
boost capacity to 160 gallons per run.
The number of compost bins needed at a site depends on:
1. The number of overnight and day visitors per year.
2. The liquid content of the wastes collected. High day use results in a higher
proportion of urine, unless urine is separated from solids.
3. The length of the compost season.
4. The capacity of the drying rack. A sewage backlog may force a shortening in the
length of a run, calling for more time on the drying rack. Hence, more storage
capacity for secondary decomposition can increase overall capacity. (In the AMC
system, the use of two composting bins in sequence permits frequent composting
runs, and eliminates the problem of sewage backlogs.)
5. How often the site and the system are maintained. If there is less maintenance
and oversight, an extra bin may be needed to provide adequate storage of wastes
and to allow a longer retention time for waste in the system. A system with less
OPERATION OF THE
SYSTEM
78—APPALACHIAN TRAIL CONFERENCE —BACKCOUNTRY SANITATION MANUAL
maintenance will not reach thermophilic temperatures as reliably, so it will need
a longer period of secondary treatment in a second bin and then on the drying
rack.
At mountain sites with an 18-week composting season, one bin and one drying rack
should be adequate for 450 to 500 overnight visitors per season. A site in the southern Appalachians, with a longer composting season and higher temperatures during
the season, could handle more visitors with one bin.
With a beyond-the-bin (BTB) system or another way of segregating urine, the number of visitors one bin can accommodate is greatly increased because the amount of
bark mulch needed to absorb liquids is reduced. AMC uses BTB systems at every
site; that, plus daily attention to the process and the use of two compost bins, accommodates high volumes of visitors.
Where two or more bins are required, they should be located side by side to facilitate waste transfer from bin to bin.
Filling the bin—If the compost bin is empty or new, add several inches of finished
compost, recycled bark, fresh hardwood bark, crumbled dry leaves, or peat moss to
the bottom. That absorbs liquid, and reduces odor. Including forest duff or recycled
compost or bark chips inoculates fresh waste with decomposer organisms.
If a run has been completed, leave the bottom six inches of material in the bin.
AMC and GMC compost operators call this bottom layer the “mank” layer. It is
generally too wet, potentially still pathogenic, and not decomposed enough to be
transferred out of the compost bin. Instead, it must be thoroughly mixed into the
waste to be composted in the next run. Add some duff or recycled compost or barks
chips to inoculate the fresh waste with decomposer organisms.
If a liquid separation method such as the beyond-the-bin system is used, there should
be little or no mank layer. In this case, leave the bottom three inches of finished
compost to help inoculate and start the next run.
Add sewage to the bin. In the bin, mix it with recycled compost, recycled bark
mulch and fresh bark mulch to the point where the wastes will not drip. The sewage
bark mixture should be glistening, not dripping.
Do not pour wastes into the compost bin. It is most efficient to have one person add
a shovel full of sewage and another person add a shovel full or two of bark or a
shovelful of old compost, and chop and mix the wastes well. Each new addition of
fresh wastes is thus broken up and mixed with bulking agent as it is added. All
mixing must be thorough.
Do not heap a large quantity of waste in the bin and then try to mix the entire batch.
This saves no time, mixing is less thorough, and more moisture drains downward.
In the AMC system, sewage from the catcher is mixed with bark mulch a little at a
time in a separate mixing bin, and then transferred into the first compost bin. This
enables very thorough mixing of the material, insuring a fast start and a high temperature during the composting process.
At low-use sites with infrequent attendance, wastes tend to dry as water settles to
the bottom of containers or is absorbed by bark mulch. When transferring such dry
waste, mix it with recycled compost from the drying rack rather than bark. Compost
usually has a higher moisture content than fresh bark, so this will help keep the
mixture moist.
9: BATCH-BIN COMPOSTING—79
It is essential to break up any clumps of raw sewage during the waste transfer. If
small clumps of raw sewage are allowed to tumble around in the bin, they will dry
slightly on the outside, and resist decomposition. Then pathogens can survive to
contaminate the finished compost. Be alert and break up any remaining clumps during
the first two turnings, while the pile is still moist and before the clumps harden.
Shake each forkful of fledgling compost when starting the run to find any sewage
clumps. Small balls of sewage will generally roll down any slope in the compost pile.
Use the side of the fork or side of the shovel to crush and cut these up.
Plan ahead: Make sure your compost bin is ready to receive sewage and start a run
when both storage containers are filled and the catcher begins to fill up.
Turning the compost pile—Thorough mixing gets the pile off to a good start and
assures aerobic conditions. Adequate mixing at any stage is not difficult if the waste
has the right moisture content. Don’t rush. Spend enough time when turning the
compost pile, breaking up clumps and regulating moisture.
Add bark mulch or dry finished compost if the pile is too wet, or add water if it gets
too dry. Keep the pile moist and steaming. Usually, the pile will self-regulate to the
proper moisture level as excess moisture drains to the bottom and forms the mank layer.
Keep the moisture level at the point where water only saturates the bottom six
inches of mank. This is the ideal moisture level. If the pile is too wet, you can
remove the lid on dry sunny days to let the pile dry.
Do not allow the pile to get too dry. Under dry conditions the process slows way
down, and some harmful micro-organisms may “encapsulate,” forming durable hard
outer coatings that protect them from attack by environmental conditions. Dry compost does not equal done compost.
Guard against adding too much bark. After a few days, wood splinters in the bark
begin to soak up moisture in the compost, and the pile will become slightly drier. In
addition, an actively turned pile will also lose moisture as water vapor escapes.
After the first few turnings of a full bin, leave the mank layer alone. Do not mix the
lower region of the bin where moisture has collected into the upper part of the pile—you
will contaminate it with pathogens.
To turn the pile, dig out a corner, taking care to leave the mank layer intact, and
heap material in the back of the bin. Dig a new hole next to the first, turning and
fluffing the compost as you fill the original hole. Work your way around the bin,
digging and filling as you go. Include the center of the pile. During a run, all portions of the pile, including the center, are actively mixed together. Add more bark,
recycled compost or recycled bark as needed. Turning may be a challenge if the bin
is nearly full, but it is essential to expose the pile thoroughly to air.
Turn the pile early in the morning to avoid blackflies and mosquitoes, or turn during a light drizzle. Slapping bugs or scratching bites is unsanitary once composting
operations have begun. Wearing long pants, a long-sleeved shirt rolled to the elbows, and a head net also helps.
The compost run—A compost run converts raw sewage to a finely textured humuslike material. Add no more new sewage to the compost bin after a run starts, because that would recontaminate the compost.
A progression of changes mark the run. The temperature of the compost moves into
the upper reaches of the mesophilic range, or 35 degrees C. to 45 degrees C. (95
See Section 3—The Decomposition and Composting Process, for
details.
80—APPALACHIAN TRAIL CONFERENCE —BACKCOUNTRY SANITATION MANUAL
Figure 9.5—Temperature profile of compost pile in a batch-bin system
during a compost run.” From the Green Mountain Club.
degrees F. to 112 degrees F.), where the most intense microbial activity takes place.
The temperature then passes into the range of thermophilic microbes (chiefly bacteria)—45 degrees C. to 75 degrees C. (112 degrees F. to 167 degrees F.). As the
upper temperature limit is reached, oxygen and readily available nutrients are depleted, and the temperature falls. Mesophilic fungi and actinomycetes begin to decay the most resistant compost components.
Turning the pile every four to five days exposes new nutrient sources, and brings
oxygen again to the pile interior. Bacterial growth is reinvigorated, and the temperature climbs again until nutrient and energy supplies are exhausted. Nutrient
and energy sources in the compost are depleted more rapidly with successive turnings. The temperature peaks get lower and lower as the pile stabilizes.
The C:N ratio begins to decline as carbon is lost as carbon dioxide. The volume of
the pile diminishes due to loss of carbon—a 30 percent reduction in pile size is not
uncommon under favorable conditions. Nitrogen is largely recycled. Although some
is lost as ammonia, the rate of loss is much less than that of carbon.
The formation of humic acids and related organic molecules darkens the color of
the pile noticeably as the process advances. Due to adsorption and assimilation of
waste compounds, unpleasant odors disappear early in the process.
Starting the compost run—A run can be conducted by one person, especially if the
operator is trained and experienced. Generally, though, it is better to have two or
more people. Two people are more likely to mix materials thoroughly without becoming tired. In addition, a helper can tend many jobs while the other person is
mixing—for example, spreading finished compost, raking compost on the drying
rack or screen, replacing the sewage catcher, cleaning the outhouse and supplying it
with bulking agent, and setting up the wash station. Finally, doing the job with two
people enables one of them to stay clean and uncontaminated if a job requires a
clean pair of hands.
See Appendix B, “Troubleshooting
and General Composting Tips.”
To ensure rapid waste breakdown and high temperatures, start a run with a large
addition of fresh wastes and hardwood bark. A full catcher (50 to 70 gallons of
sewage) works well in the GMC system. In the AMC system, a run is always started
with a full bin of new material. Once the catcher of raw sewage is mixed with bulking agent, the compost run has begun, and no new sewage wastes are added during
the run.
Stored waste—Significant decomposition can occur while sewage is stored before
the start of a run. Sometimes high temperatures are reached several times during
storage. Premature composting depletes many nutrients, so the final run may not
9: BATCH-BIN COMPOSTING—81
get hot enough without a large batch of new sewage. The result of trying to conduct
a run without enough new sewage will be incompletely composted and contaminated material. This problem does not arise with the AMC system, which does not
employ storage containers.
Large quantities are easier to compost than small ones. Pathogen destruction is more
reliable, because a large pile self-insulates and achieves high temperatures. GMC
uses 210-gallon bins to insure a high temperature, and AMC uses 160-gallon bins.
In either case, the key is to compost one large batch of sewage—as much of it fresh
as possible—at a time.
At low-use sites, too little waste may accumulate in a season for a compost run.
That is why the GMC began to use storage containers. Now, by using the 64 gallons
worth of storage and the 70-gallon catcher, a high temperature batch run can be
done even if it takes more than one season to collect enough waste.
Quantities—Using a 210-gallon composting bin, up to 160 gallons of sewage can be
composted in one run, using several hundred pounds of bark or a mixture of bark,
recycled bark and compost. Breaking up clumps, regulating moisture, and ensuring
thorough mixing is more time consuming with higher volumes, but it produces a
better result. With less than 100 gallons, reaching thermophilic conditions may be
difficult, unless the volume of use at the site is high enough that all of the sewage in
the catcher is fresh enough to mix with ample bark mulch.
Once the storage containers and catcher have been emptied, the compost bin should
be full to within several inches of the top. For slightly smaller quantities of sewage,
older compost can be added as an insulating layer around the outside of the bin. The
temperature of the pile should always be monitored if possible to make sure it is
reaching thermophilic range.
Mixing—After the final addition of raw sewage and bark, turn and mix the material
to be composted very thoroughly when starting the compost run. This provides
good starting conditions.
The AMC system requires no initial mixing in the compost bin, since sewage is
mixed with bark in a mixing bin as it is transferred to the compost bin.
Allow the compost to sit through the first temperature rise, which will probably
take about five days. Active aerobic composting will create a rapidly changing environment unfavorable to human pathogens. As oxygen and nutrients in the pile
interior are exhausted, the pile will settle slightly. If possible, use a probe thermometer to observe and confirm the temperature rise, peak, and decline. Turn the pile
again when the temperature begins to drop to reinvigorate the compost process. If
you do not have a thermometer, turn the pile after five days.
Turning the pile “inside out”—The outer layers of compost will not be exposed to the
high temperatures of the interior, and they will need to be switched with the compost in the center. This is called turning the pile inside out. The sides and top layer
are heaped into the center as the old center material is built up around them as the
new sides.
The following technique works well:
1. Dig a hole in the outer layer to within six inches of the bottom.
2. Heap this compost to one side.
82—APPALACHIAN TRAIL CONFERENCE —BACKCOUNTRY SANITATION MANUAL
3. Dig an adjacent hole in the center portion of the pile and use this compost to fill
the outside hole.
4. Dig a new outside hole to fill the center hole.
5. Continue working around the bin until all the center is moved to the outside.
The goal is to turn the entire pile inside out after each composting cycle. Since
some mixing of outsides and center compost does occur, repeat inside out mixing
as many times as the run permits.
Six turnings of the compost during a run should be the minimum. The longer the
wastes can be decomposed in the bin, the shorter will be the time needed on the
drying rack for additional decomposition. A shorter run requires a longer rest on
the drying rack for the compost.
Thermophilic conditions—Achieving thermophilic conditions is not essential to reducing the volume of waste, but it is crucial to pathogen destruction. If thermophilic temperatures are not achieved during a run, or it is uncertain whether they
have been achieved, compost should sit on the drying rack at least a year.
The AMC has found that reaching thermophilic conditions is assured at high-use
sites where the ample supply of fresh sewage is thoroughly mixed with bark mulch
before placing it in the first composting bin. Under these conditions, a separate rack
for drying and aging is not necessary.
Two bins permit a variety of strategies to manage large volumes of wastes. A run can
start in one bin, while the second is completing a run. And, as in the AMC system,
transferring material from bin to bin can simplify turning inside out.
9.6
THE FINISHED
PRODUCT
When is compost done? Unfortunately, definitive tests are expensive laboratory procedures, and composting, being a natural process, does not lend itself well to simple
field tests. However, a little experience in watching changes in temperature, color,
odor and moisture content enables an operator to reliably judge completion of the
process.
For more information on these processes, see Section 4—“Health and
Safety Issues.”
Heat, competition, aerobiosis, antibiosis, destruction of nutrients, and time are the
main agents and mechanisms of pathogen destruction. A well-managed compost
pile goes through several heat cycles during a run. The best on-site determination of
compost stability is a final drop in temperature after thermophilic conditions have
been reached several times.
A final drop in temperature may be difficult to detect, because each run behaves
differently. Fortunately, the smell and visual appearance of the compost are excellent indicators of stability and safety.
See descriptions of actinomycetes
in Section 3—“The Decomposition
and Composting Process,” and in
the Glossary in Appendix A.
At the end of a run, the compost should be loose and crumbly, with a uniform
texture. There should be no clumps or balls of sewage. The odor should be faintly
earthy, indicating the presence of actinomycetes Its color should be the dark brownblack of rich humus. The compost should be moist, not wet or dry. In general, it
finished compost looks like rich organic soil mixed with partially decayed bark mulch.
Spreading Finished Compost—Finished and sifted compost can be spread carefully
on the forest floor. The top six inches of the soil acts as a dynamic living filter made
9: BATCH-BIN COMPOSTING—83
up of plant roots, decaying plant matter, abundant soil microorganisms, and active
invertebrate populations. Nutrients and residual energy-rich compounds in the compost are quickly assimilated into this soil layer during the warmer months.
Because there is always some chance of pathogen survival, select spreading sites and
handle compost with caution. Try to avoid nutrient loading of the water table, surface water contamination from runoff, and human contact with spreading sites. Fortunately, bin composting (and aging on a drying rack if conditions require it) normally create stable and safe compost, which, if properly managed and disposed of,
presents little environmental stress or hazard to human health.
• NOTE: Check with your local Trail club, ATC field office, and land management agency
to learn of any constraints on disposing of compost. Some states may prohibit surface
spreading, so compost must be trench-buried or packed out. GMC is developing a compost incinerator that may make it easier to comply with this kind of restriction.
See Section 11.8—“Prototype
Wood-Fired Compost Incinerator.”
Keep an area map showing compost spreading zones, to enable new operators and
volunteers to locate the areas used for spreading.
When you choose an area to spread compost, look for flat ground or a gentle slope
with at least one foot of well-drained soil and actively growing herbaceous ground
plants. Avoid areas with compacted soil such as old tent sites. Water generally flows
off the surface of such sites, which should first be revegetated. Cover with leaves,
duff, and branches to initiate recovery.
Be prepared to carry compost well away from the overnight site. Some sites may
require carrying the compost for several tenths of a mile for spreading.
Do not spread compost within 500 feet of ponds and streams. Avoid natural drainages, even if they appear dry. They are often indicators of subsurface flow, and they
will be wet if it rains. Avoid marshy areas, as groundwater will be near or at the
surface. Never spread within 1,000 feet upslope of any drinking water source.
Spread compost only in the summer. Dissolved minerals and residual pathogens are
much more likely to be leached into water at other times of year. Try not to spread
compost during or immediately before a rainstorm. This will allow extra time for
assimilation into the soil.
Spreading compost, like starting a run, is best done with two people, both to facilitate carrying the compost to the spreading site, and to speed the process. Five-gallon grout buckets are good for carrying compost. A 20-gallon can is the largest container two people can carry any distance. It is better to use smaller containers and
avoid fatigue, which creates temptation not to travel far enough.
Feed sacks or coffee bags can also be used, either filled with compost or used as slings
carried by two people on each end. However, moving compost with bags is not as
clean as transport in a can or bucket.
Set the can or bag with compost on the ground at the edge of the selected spreading
area. Scoop up a shovelful at a time and scatter it thinly over the ground to prevent
overloading any spot with nutrients. Throwing the compost into the branches of
small trees helps scatter it. Do not dump compost, fling a large quantity from the
container, or drop shovelfuls on the ground in small heaps. Ensure clean working
procedures.
See Section 4—“Health and Safety
Issues.”
84—APPALACHIAN TRAIL CONFERENCE —BACKCOUNTRY SANITATION MANUAL
9.7
COMPOSTING RECORDS
Accurate record keeping is important, both to the success of a long term operation
and to orienting new operators. Many problems can be easily avoided if information
is passed along in a useful manner.
In addition to filling out the record forms, each operator should write a report summarizing the operation and problems encountered during the season, and recording
the status of compost system at the start of winter.
How to fill out the composting record form—Composting record forms indicate
the actions taken regarding the compost bin and drying rack. It is not necessary to
record each time you empty the collection container into a storage container, although this can be useful for scheduling visits to composting sites. Record actions
such as mixing the wastes in the storage container in the “Comments” column.
1. Date—The record form should be filled out only when something is done to the
compost bin or drying rack, such as adding sewage or bark, turning and mixing,
removing compost, etc.
2. # Visitors—This should not be a cumulative figure. Record the number of overnight visitors from date to date, including the site attendant(s), if any. Note in
the comments the approximate number of day users.
3. Sewage Input—This is the volume of raw sewage added to the bin, in gallons or
liters. Estimate the quantity by the fullness of the catcher and storage containers.
Subtract the volume of bark that you have added to the catcher or storage containers, so you have computed the net volume of raw sewage.
4. Bark Input—Again, this is the amount of fresh bark added to the bin, by the
operator when a run was begun. Estimate the weight and record in pounds or
kilograms.
5. User-Added Bark—Record the quantity added by users in the outhouse, and the
amount added to the collection container by the operator. This column is totaled up and added to the total bark input column when a run begins. Record it
as often as necessary—generally as a bag is used up in the outhouse.
6. Recycled Compost Input—Record here the quantity of old compost or recycled
chips added to the bin and mixed with the fresh wastes.
7. Date Full—This is the date that a run begins. After this, no fresh sewage is added
until the completion of the run.
8. Total Sewage Input—Add up the number of gallons of new sewage collected since
the end of the last run. Do not include mank left in the bin from the previous
run.
9. Total Bark Input—Add up the pounds of fresh bark added to the bin when the last
run was begun plus the pounds of user added bark which have also been added to
the catcher. Again, do not consider recycled compost or bark mulch used as bulking
agent or mank left over from the last run.
10. Pile temperature—If a thermometer is used, record temperatures daily. If no thermometer is used, estimate temperature and record as thermophilic (thermo) or
mesophilic (meso).
9: BATCH-BIN COMPOSTING—85
11. Turning Dates—Record each date the pile is turned during the run.
12. Date Complete—This is the date the run is over and the finished compost is
transferred out of the bin. Fill the entire line to give a summary of the run.
Under “Turning Dates,” record the number of turnings. If a second run is begun
on the same day, begin a second line to record this new operation.
13. Compost Transferred to Drying Rack—Record in gallons or liters the approximate volume of compost which is transferred to the drying rack.
14. Observations and Comments—Be as specific as possible. Things to record here
include: pile turned and mixed; pile moisture, color, and odor; temperature status; amount of old compost added to the process; problems encountered; presence of fungi or actinomycetes; presence of invertebrates; status of compost on
the drying rack; information on spreading compost (where, how much—an area
map is helpful), etc.
9.8
Before the hiking season begins, the project leader should visit each site with field
personnel or volunteers to empty the catcher and plan for the composting season.
SPRING START-UP
PROCEDURES
Generally, all that is needed on the first visit, if the storage containers were left
empty the previous fall, is to empty the catcher and scour the site for wastes deposited on the snow by thoughtless winter users. Use the red-handled shovel to add this
waste to the storage container.
Take antibacterial soap and a wash jug with you on the first trip, because there may
be none at the site.
Typical problems to be dealt with in the spring may include a large amount of accumulated wastes to be composted; fecal wastes from snow holes on the snow and the
ground; and the bin lid knocked off during the winter, letting water into the bin.
Securely fastened lids should stay on bins. However, they can still be knocked off by
falling trees, and determined vandals can defeat any fastening system, so it is best
not to leave material in composting bins over the winter.
You may find a soupy mess if storage container lids were knocked off during the
winter, or the storage containers were knocked over. You may find bark burned or
thrown in the snow over the winter, trash in the storage container or collection
container, and so forth.
Review the records and the report of the previous operator for existing problems.
Look for new problems. Develop a waste handling and management timetable with
the individual operators.
The plan of action for each site should address:
The catcher: Does it need to be emptied immediately? (It generally does in the
spring.) Does it need replacement? When? Etc.
The compost bin: Is it full? (It is best to leave it empty the preceding fall.) Is
compost ready for transfer to the storage platform? Does it need more wastes
before starting a run? Does it need bark? Turning? Etc.
See sanitary procedures in Section
4—“Health and Safety Issues.”
86—APPALACHIAN TRAIL CONFERENCE —BACKCOUNTRY SANITATION MANUAL
The storage containers: Are they full? When will they be full? Do they need replacement? When? Etc.
The drying rack: When will space on the rack be needed? Is compost ready for
sifting? Does it need new siding, bottom boards, roof? Etc.
Evaluate all other components of the composting system, including shovels, other
tools, plastic wash jug, antibacterial soap, probe thermometer.
An example of a spring action plan might be:
•
•
•
•
Spread last year’s compost from half of the storage platform
Repair platform
Turn and mix remaining compost on the drying rack for further aging
Begin a run with the new wastes
Plan a follow-up visit by the project leader, particularly for first-year compost operators. Problems at the site may require immediate attention.
Overwintered compost from a drying rack can be recycled into the catcher and
compost bin to minimize bark use. Turn and aerate it directly on the drying rack
with the green fork to speed aging. Remember that compost absorbs less moisture
than fresh ground hardwood bark.
Evaluate and anticipate compost accumulation on the drying rack, and plan a spreading schedule. Rapid plant growth and actively growing ground microbes and soil
flora and fauna create optimum spreading conditions in midsummer. Plan ahead.
In the Northeast, mud season is generally a month of low waste accumulation, so try
to get as far ahead as possible. If large volumes of waste are anticipated at a mediumto high-use site, try to run the previous winter’s waste with enough new sewage to
have a four-week run done by the July 4 weekend.
Use June to get a few extra bags of bark on site. Stay several bags ahead at all times,
so extra bark will be on site at the end of the season for the next year.
Never panic; just get the job done.
9.9
END-OF-THE-SEASON
PROCEDURES
Because the AMC system uses two bins, one will be available to start composting in
the spring, or as a repository for sewage if the catcher fills during the winter, even if
the other bin has been left full during the winter. Freezing of the comparatively dry
compost does not damage composting bins. However, with any system it is best to
leave all bins empty during the winter. Otherwise, users of the site are apt to find a
way to remove lids, allowing a nicely finished bin of compost to become waterlogged and mixed with trash. The bins are covered with watertight lids tied in place.
The drying screen is left empty, with the tarp flat on the screen and held in place
with rocks.
In the GMC system, schedule your last run of the season so the compost bin can be
emptied before winter starts.
Leave the catcher empty to allow for late fall and winter accumulation. Disconnect
the beyond-the-bin or other liquid separation system if one is present before temperatures fall below freezing.
9: BATCH-BIN COMPOSTING—87
Late fall is not a good time to spread compost. Leave it on the drying rack or screen—
or the second bin in the AMC system—until the next summer.
In the GMC system, provide space on the drying rack to accept compost from a fall
run, so the compost bin will be empty (except for the mank layer) through the
winter. To do that, spread compost from the rack as early in the fall as possible, but
no later than mid-September. Compost stored over the winter on a rack is generally
ready for spreading or recycling as early as mid-June if it is turned several times.
Outhouses, particularly those depending on composting, benefit from attention in
winter, unless there is no winter use. Regular visits to batch-bin composter sites in
the winter are desirable. Solicit shelter adopters or other volunteers to check the
storage containers, shovel snow from the outhouse door and the rear access door,
and empty the catcher if it fills. Often former caretakers will be willing to do this,
and some hikers also may be willing. Demonstrate procedures to volunteers in the
fall, and post signs at the outhouse with instructions.
In the GMC system, at least one of the storage containers should be left empty.
That will allow the catcher to be emptied in the fall, winter and spring.
Leave several bags of bark on site, under cover if possible. The GMC has found six
bags is the ideal amount to get things rolling in the spring: two for use in the outhouse by hikers, and four for use in starting the first run of the next season. There is
enough to do in the spring without having to pack in six bags of bark to deal with
winter wastes.
A brief report should be added to the compost records and sent to the shelter adopter,
if there is one, and to the maintaining club. Point out problems encountered, how
they were dealt with, and what to expect. Evaluate all parts of the batch-bin system.
Secure the compost-bin lid with rope and stakes or with several heavy rocks. If the
area is subject to high winter use, consider placing hooks on the lid or locking it
down with carriage bolts to keep the curious and litterbugs from peeking inside.
GMC has learned that secure fastening of lids is vital. Looking for the dumpster
they have been hoping to find all along the Trail, hikers often do not realize what is
in the bin, despite signage. When they finally pry the lid off, they are horrified by
the contents and leave without replacing the lid. Then the bin fills with contaminated water which must be bailed in the spring and carefully dumped in a sump hole
away from water, facilities and trails.
Be sure the roof on the drying rack is intact and secure. Scan the area for dead trees
that could fall on the composting operations and outhouse, and, if necessary, remove them.
Store composting tools where they may be easily retrieved: hanging from trees near
the drying rack and outhouse, unless experience indicates they must be in a secure
locker. Record where the tools are stored. Bring the thermometer indoors for the
winter.
9.10
Winter is a time of suspended decomposition. Human fecal waste in pit privies,
catchers, and storage containers breaks down extremely slowly, if at all. No
composting is done in winter, but if a site receives heavy winter use, a midwinter
emptying of the catcher may be necessary.
WINTER OPERATING
PROCEDURE (USUALLY
OPTIONAL)
88—APPALACHIAN TRAIL CONFERENCE —BACKCOUNTRY SANITATION MANUAL
GMC and AMC have found that their new 70-gallon catchers do not overflow
during winter if they are emptied in late fall, so their sites no longer need winter
visits. If a site has such high winter use that a 70-gallon catcher is overwhelmed,
winter attention will be necessary, unless it is possible to convert to an even larger
catcher.
When checking shelters or campsites used in the winter, check for defecation on
the snow and in snow holes near or above the water supply, and shovel any feces
found into a storage container. Make sure the outhouse door is free of snow and ice
and that the catcher has not overflowed, driving people outside. Make sure there is
enough bark in the outhouse.
Wastes left on top of snow are partially broken down by weathering and sunlight,
but wastes left in deep snow holes will emerge in late spring. When the snow melts,
human wastes may directly enter surface water. Spring runoff contamination potential is highest at overnight shelters next to water.
For emptying the catcher in winter, you need old leather work mittens, a snow
shovel, a one-quart tin can, soap, and a small camping stove. The can, soap, and
stove are for hand washing (a Thermos of hot water can be substituted for the stove).
Find the composting tools, both red and green. They should be hanging on trees
near the drying rack and the outhouse. Check the records before you start.
Shovel a path to the outhouse, shovel out the outhouse, and shovel a path to the
storage containers. Check the storage containers to see whether they will hold more
waste. If not, check the bin to see if wastes can be placed directly in the bin. This is
a last resort, because it complicates emptying the bin and starting a run early the
next season.
If you are alone, boil a can full of water, and place it in the outhouse for washing up
afterward. Bringing it to a full boil assures it will be warm when you are done. If the
weather is extremely cold, cover the can with a spare jacket or something else to
conserve its warmth. If you’re not solo, have your companion take charge of the hot
water. Soap dissolves poorly in ice water, so washing hands in cold water is ineffective as well as uncomfortable.
Put on your pair of old leather mittens, which you will drop in a plastic bag to be
cleaned at home when you are done. Remove the catcher from the outhouse, being
careful not to twist it or bend it. If urine has run down the front, the catcher may be
frozen in. If so, use the tip of the red shovel to pry it up. Several sharp blows with a
board to the gap between catcher and outhouse will generally free it. Be careful:
Plastic breaks easily when very cold. Hot water can be used to melt the troublesome
ice, if you can make enough of it.
Check to be sure the bottom of the catcher is intact. (If it is not, transfer all accumulated waste to a storage container. Leakage should be mopped up with bark mulch
and also placed in a storage container. Use a five-gallon bucket as a temporary substitute catcher, and plan to replace the catcher immediately. Place the old catcher
in a secluded spot in the woods to weather for a year before packing it out.)
Place the catcher next to the storage containers. Transfer the waste to the storage
containers. If the material is not entirely frozen, it can be shoveled directly into the
storage container. Otherwise, use the red shovel (not the fork) to shave the wastes,
one thin layer at a time. This generally works well, but it is time consuming (oneand-a-half to two hours for 70 gallons of waste). Sometimes, if plenty of bark was
left in the bottom of the catcher, the block of waste will slip right out.
9: BATCH-BIN COMPOSTING—89
Pick up any shavings or chips of waste from the snow with the red shovel, and put
them in the storage container. Re-secure the covers of the storage containers to
keep out hikers’ trash.
Replace the catcher in the outhouse, taking care to line it up properly. Usually it
should be as far forward as possible, to keep urine from running over the front edge
and freezing the catcher to the outhouse. Close the rear door securely. Loosen the
bark in the container in the outhouse, and line the bottom of the catcher with three
inches of bark to absorb liquid and reduce odor.
Replace the red shovel. Wash up. Record data in the record book. Post new signs if
needed.
10
Liquid Separation in Composting
Systems (AMC’s Beyond-the-Bin
System)
Hawk Metheny, Shelters Field Supervisor, Appalachian Mountain Club
10.1
WHEN TO USE A
BEYOND-THE-BIN-SYSTEM
One of the biggest drawbacks to a conventional batch-bin composting system is the
challenge of transporting bark mulch to a backcountry location. Backpacking, helicopters, and pack stock involve labor and expense that rise to formidable levels at
remote sites that encounter high use.
The beyond-the-bin (BTB) system was developed by the Appalachian Mountain
Club in 1995 to reduce the amount of hardwood bark being flown or packed to its
fourteen remote backcountry campsites, all of which use composting toilets. Those
sites collectively average more than 20,000 users per year. Two BTB systems were
installed in 1995, four in 1996, four in 1997, and two in 1998, for a total of twelve.
The remaining two sites still use the conventional batch-bin system. One is in a
federally designated Wilderness area, where airlifting is not allowed and getting
conversion materials to the site would be problematic; the other site sees comparatively low use and does not warrant the conversion.
With twelve sites using the BTB system there has been a reduction in bark consumption of 30 to 35 percent. In 2000, the AMC shelter program airlifted more
than 400 fifty-pound bags of bark. Some sites use more than 40 bags per season.
Without the BTB, demand for bark would have been more than 600 bags (15 tons),
with the most popular sites needing more than 60 bags. The Bell Jet Ranger helicopter used for airlifting carries 800 pounds and costs $800 per hour. Saving more
than 200 bags of bark has reduced airlift costs by about $2,400 a year, and has also
reduced noise and visual impact on backcountry visitors.
10:
L IQUID
S EPARATION
IN
C OMPOSTING
10.2
Traditional batch-bin composting systems collect urine and feces in a collector
vessel, or catcher, under the outhouse seat. In the BTB system, a sturdy strainer
plate is installed in the collector as a false bottom, so solids remain on top and
liquids pass through the strainer. A fitting and drain hose at the bottom of the
chamber below the strainer carry the effluent to a filter barrel filled with anthracite coal and septic stone, where it is treated safely and dispersed into the
soil through perforations. (See Figure 10.x). That substantially reduces the
amount of liquid in the collector.
The ideal moisture content for composting is around 60 percent. Coincidentally,
the average moisture content of human fecal matter is 60 to 70 percent. But urine
raises the moisture content, so additional bark is needed to absorb the liquid.
In addition, the ideal carbon-to-nitrogen ratio (C:N ratio) for composting is thirty
parts carbon to one part nitrogen by weight, or 30:1. Fecal matter has a C:N ratio of
about 8:1, and hardwood bark has a C:N ratio of about 150:1. When mixed in the
Figure 10.1—The beyond-the-bin liquid management system designed by the Appalachian Mountain Club’s Trails Department. This system is an improvement to the Green
Mountain Club and Appalachian Mountain Club batch-bin system. Not shown in this
diagram is a second barrel that can be attached beyond filter barrel to store filtered
effluent. This allows the system to be located near water or in places where drainage
is poor. Treated effluent drains into the storage barrel, and is transported to a site with
better characteristics for disposal in the ground.” Diagram from the Appalachian Mountain Club Trails Dept.
OVERVIEW
S YSTEMS —91
92—APPALACHIAN TRAIL CONFERENCE —BACKCOUNTRY SANITATION MANUAL
Figure 10.2—Diagram illustrating the placement of a perforated stainless-steel strainer
plate in a 70-gallon sewage catcher. This is the first step to attaching a beyond-the-bin
liquid management system. The hose leads liquid away for treatment. Diagram from
the Appalachian Mountain Club Trails Department.”
ratio of about two parts bark to one part waste, the desired C:N ratio of 30:1 is
achieved. Excessive urine raises the nitrogen ratio so that more bark, with its higher
carbon ratio, is needed to offset the urine’s higher nitrogen level. Traditional batchbin composters generally require three parts bark to one part waste to achieve the
desired 30:1 C:N ratio.
Signs and on-site managers asking users not to urinate in the outhouse help achieve
some reduction in the amount of urine. Even then, however, human biology and
anatomy, combined with the preference of some users to urinate in private, inevitably add some urine to the catcher, especially in high-use areas.
10.3
BENEFITS AND
DRAWBACKS
Additional benefits—The beyond-the-bin system has benefits beyond conserving
bark. Handling raw sewage is inherently unpleasant and risky, and excessive liquid
makes it much worse. Removing liquid lessens spillage, reducing risk to both the
operator and the environment.
Another advantage is improved recycling of mulch. The BTB system creates drier
compost, so less bark decomposes and more is recovered by sifting.
Separating liquid also reduces odors. Most offensive odors are due to ammonia and
other products of anaerobic decomposition, especially when urine is mixed with
feces. The BTB systems have a slightly musty odor that is not nearly as offensive as
pit privies or the occasional catcher in traditional bin-composting systems. That
10:
L IQUID
S EPARATION
IN
encourages hikers and campers to use the outhouse rather than the forest floor as
long as the toilet seat, hopper, and outhouse floor are kept clean.
Installing a BTB system is not complicated, and it requires only basic carpentry
and plumbing skills. Fortunately, the slight slope needed to make liquids flow
downhill is usually available with little or no modification to the landscape.
Since the system is driven by gravity, only the plumbing parts require routine
maintenance and repair.
Unless the compost in a traditional composter has the perfect water content, which
is not often the case, the bottom of the bin accumulates a layer of wet, non-composted
sewage with a distinctive odor that operators call “mank.” After the compost layer
above is removed, bark is mixed with this layer to absorb the liquid and restart
proper composting. Mank seems to accumulate because liquids settle through the
pile, and it is virtually eliminated in the beyond-the-bin system.
Drawbacks—Moderately higher initial investment is the biggest drawback to the
BTB system. It requires a collection tank, strainer plate, plumbing parts, and filtration system. However, the saving in labor and mulch transport soon offset these
expenses.
If funds are limited, the system can be set up in stages. The strainer, plumbing, and
filtration system can be installed later in a batch-bin composting system as long as
clearance for the collection tank is provided in the initial construction, and a 70gallon Rubbermaid catcher is installed.
One other drawback is that the compost may be harder to mix. When solids and liquids
are combined, the liquid helps soften the solids, sometimes even dissolving them completely. In the BTB system, clumps of sewage tend to stay bonded, so breaking down
solids is more laborious, and diligence and attention to detail are required to properly
mix the material. However, the compost pile requires fewer turnings. Therefore, the
total work of turning the pile is about the same for the two systems.
The BTB system has slightly higher visual impact because of the drain pipe and
filter barrel, but careful design and attention to detail during construction can help.
Pipes can be buried or routed through brush. The filter barrel can be almost completely buried, since only the cover need be accessible for monitoring and periodic
replacement of the filter medium.
Special Considerations—A sturdy portable intermediate mixing container is a useful component in the beyond the bin system for proper mixing of sewage and bark.
In traditional batch-bin composters, sewage is usually mixed in the compost bin.
Since extra effort is needed to break up sewage balls and clumps in a BTB system,
the mixing container must be strong to withstand vigorous shovel and pitchfork
handling. Stainless steel and thick plastic containers work well, and there may also
be other possibilities.
As with most compost systems (the moldering privy is an exception), dry bark is
vital. Thorough drying before bagging and dry storage on site are crucial. Store your
dry bark in synthetic feed bags lined with plastic bags under a tarp.
The filtration system should be disconnected after the final compost run of the
season to prevent freezing and splitting the drain pipe in winter. A quick-disconnect fitting on the pipe simplifies this.
Filter materials may eventually need replacement. AMC has had its systems in place
for five years, and testing the effluent from the first system shows it still met the
C OMPOSTING
S YSTEMS —93
94—APPALACHIAN TRAIL CONFERENCE —BACKCOUNTRY SANITATION MANUAL
standards required for backcountry dispersal. We recommend testing effluent every
five-years.
10.4
DRYING THE END
PRODUCT
Screens dry and sift the finished product. Raised four-foot-by-eight-foot screens made
of half-inch-by-#18 expanded stainless steel or galvanized metal are mounted on a
frame of pressure-treated “2-by-4” lumber. Compost is spread on the screens from
the second compost bin and allowed to dry for several days. Next, the material is
sifted using shovel, spading fork, or gloved hand, so the fine humus falls through the
screen and intact bark stays on top.
For details on proper procedure,
see “Spreading Finished Compost”
in 9.6 above in the chapter on
Batch-Bin Composting.
The humus is gathered in buckets or feed bags and carried away from the campsite
for dispersal and broadcast on the forest floor. Bark remaining on the screen is
allowed to dry further, and then bagged in plastic-lined feed bags to be re-used in
subsequent compost runs. (Incidentally, do not put recycled bark in the outhouse;
use only new, clean bark there.) The drying screens are covered with tarps nightly
and during inclement weather. The tarp is supported by a raised ridgepole of 2-by-4
lumber.
Screens increase the re-usability of bark significantly, further reducing the need to
transport more bark to remote sites.
10.5
INSTALLATION
Three or four people can install a BTB system in a couple of days. Following is a
brief description of the installation. More detailed instructions are available from
AMC. (See Appendix TK for contact information.)
Elevation Change—First, determine whether your site has adequate slope for a gravity-fed filter system; it must be at least 1⁄8 inch per foot, though a steeper angle is
better. If necessary, the outhouse base and collector support rails can be raised to
gain elevation.
Size of collector housing—AMC uses 70-gallon catchers in its privies to accommodate a high volume of visitors. Some of our sites in the White Mountains of New
Hampshire average twenty visitors per night, with peak nights over sixty. The catcher
is 24 inches tall, and weighs more than 550 pounds when full, so it requires a substantial housing. Our outhouse bases sit on a foundation of pressure-treated “6-by6” lumber. The catcher sits on a pair of rails of pressure-treated “4-by-4” lumber for
easy extraction through the access hatch. If the BTB system is to be installed in an
existing composting system, outhouses can be retrofitted, or a collection unit with a
lower height might be adapted or modified.
We have designed a base to fit a standard four-by-four-foot outhouse supported by
timbers of 6-by-6 lumber stacked in five or six layers and secured with hundredpenny nails. All lumber can be cut in the frontcountry and then transported to the
site. The timbers are best cut with a sharp chain saw by a skilled sawyer.
Plumbing parts are readily available, and some pre-assembly can be done in the
shop to insure all pieces are accounted for and fit together. The filter barrel perforation holes are also best drilled before transporting to the backcountry, although
they can be drilled on site with a cordless drill. Approximately 75-100 pounds of
septic stone is required, along with five or six 50-pound bags of fine grade anthracite
coal. These materials are widely available.
10: LIQUID SEPARATION IN COMPOSTING SYSTEMS—95
The majority of the installation time and effort will go into building the outhouse
and its base.
Distance from Water—The filter should be at least 100 feet from any pond, lake, or
stream, and more is better. If this is not possible, install a second barrel connected
by a hose to the filter barrel (which must not be perforated) to collect liquids, which
can be pumped or bailed for disposal in a better spot. Use sturdy capped jugs to carry
the filtered effluent.
Regulations—Local and/or state authorities may call for specific designs for final
distribution of liquid effluent that should not be required for a BTB system. It is
important to remember the very small flow being treated. Most authorities are accustomed to flows in the hundreds of gallons per day generated by conventional
flush systems, not the quarts per day from a waterless composting system. Be sure to
clearly explain this fact and to describe the BTB system as a vast improvement over
the pit privy being replaced.
10.6
The beyond-the-bin composting system is a substantial improvement over a conventional batch-bin composter, especially in high-use areas. The moderate initial
financial investment will be quickly repaid through reduced bark transportation,
higher quality end product, less odor and a safer and more pleasant experience for
composting personnel.
CONCLUSION
Part 4
Installations
11—Case Studies
Moldering Privy on the A.T. at Little Rock Pond, Vermont
Moldering Privy on the A.T. in Massachusetts
Appalachian Mountain Club Clivus Multrum Composting Toilet
Randolph Mountain Club Bio-Sun Composting Toilet
At Home with the Clivus Multrum Composting Toilet
Airlift Haul-Out Systems
Flush Toilets with Leach Field at High Mountain Huts
Prototype Wood-Fired Compost Incinerator
12—The Decision Making Process
13—Gray Water Management in the Backcountry
11
Case Studies
11.1
MOLDERING PRIVY
ON THE A.T. AT
LITTLE ROCK POND,
VERMONT
By Dick Andrews, Volunteer, Green Mountain Club
The first experimental moldering privy was installed at Little Rock Pond Shelter on
the Long Trail/Appalachian Trail in the Green Mountain National Forest in Vermont in September 1997, under the supervision of Dave Hardy, field supervisor for
the Green Mountain Club (GMC), with help from me.
The moldering privy replaced a pit privy located on a steep slope—actually, an
ancient talus slope with thin soil, where finding new places to dig pits was extremely
difficult. The outhouse at the site was in poor condition, so we replaced it with a
new one prefabricated by a GMC volunteer. A large group of volunteers on a freshman orientation outing from Harvard College helped carry materials about three
quarters of a mile up a stiff grade on a side trail to the site, and helped build the
privy.
After removing the old outhouse, we backfilled the pit to within a few inches of the
top. We then built a crib over the original pit, using six timbers of white “8-by-8”
cedar landscaping lumber, in three courses of two timbers per course, resulting in
horizontal gaps of eight inches in the crib. The timbers were excellent for the purpose: light to carry and easy to work, but sturdy and decay-resistant. They were
fastened with long spikes without pre-drilling holes.
The timbers varied in length from four feet long to somewhat more than six feet
long. To maximize the volume in the crib and minimize waste of the timbers, we
built the crib in the form of a stepped truncated pyramid, wider at the base than at
the top. It was two feet high, providing somewhat more than two vertical feet for
waste accumulation, counting the depression below the crib and the elevation of
the floor of the outhouse above it. Total volume in the crib was about 40 cubic feet.
After sending volunteers far and wide for forest duff and stapling hardware cloth
and insect screening over the gaps in the crib, we placed about eight inches of duff
in the bottom of the crib, and banked duff against its sloping sides. We assembled
11: CASE STUDIES—MOLDERING PRIVY IN VERMONT—99
the outhouse on top of the crib, lightly toenailing it in place to ease removal when
the crib filled. The design of the outhouse was conventional, with a seat on a wooden
bench at the rear of the structure. We did not install a vent, since the porous duff
banked against the crib allowed ample ventilation while excluding light and insulating the compost pile somewhat against temperature variations. The last step was
the installation of a few steps to reach the door of the elevated outhouse.
Little Rock Pond has a caretaker in summer, and the caretaker keeps the privy supplied with bulking agent. We started with bark mulch, but switched to softwood
shavings (eastern white pine, available at agricultural supply stores), which were
lighter to backpack to the site, easier to manipulate in the pile, and easier and more
attractive for users to handle. A nine-cubic-foot bale, compressed to a package 12by 18-by-28 inches, weighed 35 pounds and cost about $3. It was enough for more
than 1,000 uses, at one cup per use. Users were asked to add a handful of shavings
each time they use the privy.
See Appendix F for a copy of the
stewardship sign with instructions
for users.
The caretaker keeps an eye on the compost pile, stirring with a stick and watering
with a garden watering can through the toilet opening as needed to keep the pile
aerated and moist. Each season the GMC has introduced an eight-ounce container
of redworms to enhance composting in the pile. The club propagates its own worms
in plastic buckets at headquarters in Waterbury Center, Vermont.
Composting has worked well in the moldering privy, and as of the end of the 2000
hiking season, the crib had plenty of room for additional use. In the privy’s first full
season (the summer of 1998), A.T. thru-hikers repeatedly wrote in the shelter log
book that the moldering privy was the nicest smelling outhouse between there and
Georgia. Reviews have continued to be complimentary. The privy is not odorless,
but the odor is usually earthy, as long as the pile is at least lightly covered with
shavings.
When the crib does fill, a second crib will be built and the outhouse will be moved
to it, an easy job for four people using a couple of 2-by-4s temporarily nailed to the
walls of the outhouse as handles. The first crib will be covered with a layer of forest
duff (protected from dogs or other animals by a hardware cloth cover) and left to
weather and finish composting until the second crib is full. Then it can be emptied
and the compost scattered on the forest floor at an appropriate distance from water,
trails and the shelter site.
11.2
By Pete Rentz, M.D., Trails Chairman, Massachusetts A.T. Committee of
the AMC-Berkshire Chapter
The ideal composting system would be safe for users, safe for maintainers and the
environment, easy to use, durable, and lightweight for ease of transport. It also would
be economical, and the composting process would use a readily available bulking
agent. In Massachusetts, we have been experimenting for several years with a design
for a moldering privy that attempts to achieve those goals.
We started with our basic four-foot-by-four-foot privy, which we know how to transport and build, and placed it on a cribwork of 6-by-6 timbers that form two composting
chambers. We have found that even in a high-use situation, a nine-cubic-foot chamber will require more than a season to fill with feces, organic material, and toilet
MOLDERING PRIVY
ON THE A.T. IN
MASSACHUSETTS
100—APPALACHIAN TRAIL CONFERENCE —BACKCOUNTRY SANITATION MANUAL
paper. When this occurs, the privy is simply shifted to the empty adjacent chamber.
Thus, composting occurs for a minimum of one year, and in some cases two or three
years. During that time the volume of compost typically halves, and the end product is not much different in appearance and smell from the original carbon-rich
forest duff (partly decomposed leaf litter) that we use for a bulking agent.
We use duff for the carbonaceous composting material because it is free, it is available everywhere in the woods without need for transport, and it does not introduce
foreign substances into the natural environment. Duff is also desirable because it is
finely divided and fluffy, and because it contains a rich assortment of aerobic soil
bacteria, molds, and fungi.
Since the composting crib is in contact with the soil, earthworms will be found in
the compost. We have tried to introduce red wiggler manure worms (Eisenia foetida),
but have not seen any indication that they speed the composting process. In fact,
they disappear soon after they are introduced, and may only serve as a feast for
shrews.
We have tried urine diversion, and have found that it is important for our high-use
moldering privies to prevent saturation of the compost pile. The composting chamber of a low-use moldering privy fills only every two years; in this situation, the
urine appears to evaporate or percolate through the compost pile to the soil satisfactorily.
Urine diversion is accomplished by creating a “two-holer,” with one seat for urination only. The urine basin is a six-quart stainless steel mixing bowl fitted with a sink
drain that is plumbed to a length of 1⁄2-inch internal diameter thick-wall clear plastic tubing. The end of the tubing is perforated and is placed in a small leach pit
containing landscape fabric, gravel, and anthracite coal. The urine diversion apparatus adds about $100 to the cost of our privy.
There is no odor associated with the leach pit. However, it is good to flush the basin
and tube periodically with a quart of clean water. Beyond this ordinary cleanliness,
disinfection of the plumbing with chlorine solutions has not proven necessary. The
urine diversion feature mainly serves women; men are encouraged to urinate on
trees at a decent distance from the shelter.
We have tried covering the composting chamber with a weather-resistant board,
but it has proven to be unnecessary. The cover doesn’t seem to make much difference to the composting process. Rain and evaporation seem to balance each other
in our uncovered chamber experiment. The cover is mostly for aesthetics, and a
layer of dry leaves appears to be equally good for this purpose.
Mixing is performed yearly with a spading fork. This aerates the compost, and breaks
up tree roots that might otherwise infiltrate the compost. The final product, about
four cubic feet of humus, is carried a short distance in five-gallon plastic buckets to
a disposal area where it is buried in a spot away from foot traffic and downhill of any
water source.
Those procedures require about one hour of maintenance activity each year per
privy, not counting the harvesting of duff, which is usually performed by the users in
accordance with simple instructions. Compare tht to the three to four man-hours
necessary to re-dig a pit privy and move it.
We ask users to deposit one handful of duff per use of the toilet. An instructional
sign directs hikers to places to collect duff, and asks them to try to collect duff with
deciduous leaves that have begun to decay and are rich in decomposing organisms.
11: CASE STUDIES—MOLDERING PRIVY IN MASSACHUSETTS—101
It directs them not to dig deep enough to create holes that could cause erosion. It is
good to keep a small rake for collecting duff, since that encourages harvesting the
renewable upper layer rather than digging into the soil. The sign also instructs hikers not to harvest in a spot already harvested.
Flies and other vectors have not been a significant problem. The composting privy
is sweeter-smelling than the pit privy it replaces, and appears to attract fewer insects.
11.3
By Chris Thayer, Huts Manager, Appalachian Mountain Club
The Appalachian Mountain Club (AMC) has increasingly relied on Clivus Multrum
technology in recent years to provide sanitation at our high-elevation huts in the
White Mountains of New Hampshire. The eight huts, spaced about a day’s hike
apart, are located near or above timberline, where there is little or no soil. The
White Mountains have such a severe climate that they have pockets of permafrost
and have recorded the world’s highest surface wind velocity. The staffed and fully
enclosed huts provide meals and bunkroom-style shelter.
Since 1997, we have installed Clivus Multrum continuous composting toilets at
Carter Notch, Mizpah Spring, Galehead, and Lonesome Lake Huts with great success. The success of this innovative technology at backcountry locations serving 36
to 60 guests per night is promising for applications in the frontcountry as well.
Construction costs varied, depending on the size of the system and whether it could
be installed in an existing structure. Costs ranged from $60,000 at Carter Notch,
Galehead, and Lonesome Lake (for four toilets at each hut), to $85,000 at Mizpah
Figure 11.1—Example of large, commercially designed, continuous composting toilet. This example
is a schematic cutaway view of a Clivus Multrum
system, showing features common to most models.
(Contact Clivus Multrum New England for specific
model information. See Commercial Systems contacts in the Appendix.) As waste composts, it becomes light and crumbly, and slowly migrates via
gravity down the sloped bottom to an access port,
where finished material is removed. Provisions are
made to remove and treat liquid effluent separately.
This step is essential to the proper composting of
material in a large continuous composting system,
especially in backcountry settings. In backcountry
and mountain environments, cold temperatures and
high humidity usually prevent most liquid from
evaporating.” Diagram from Clivus New England and
The Composting Toilet System Book by David Del
Porto and Carol Steinfeld.
THE APPALACHIAN MOUNTAIN CLUB CLIVUS
MULTRUM COMPOSTING
TOILET
102—APPALACHIAN TRAIL CONFERENCE —BACKCOUNTRY SANITATION MANUAL
Spring (for six toilets). Though there is significant investment upfront, we have
found these systems cheapest to operate at high-use sites in the long run.
The schematic (Figure 11.x) shows a cutaway view of the composting chamber. The
waste mass is similar to a garden compost pile. Shoveling out a small amount of
composted final product each year creates a void that causes the waste in the pile to
slowly slide down the inclined back of the bin as it decomposes. The chambers are
sized so that waste is completely composted in the two or more years it takes to
appear in the lower hatch.
That end-product, reduced to only 5 percent of its original volume, has the odor,
appearance, and bacterial content of topsoil. Liquid that appears in the sump reached
by the lower hatch has changed biochemically to a stable fertilizer and salt solution
safe enough to meet quality standards for swimming water!
The vent on the composter, assisted by a solar-powered electric fan, creates a draft
that pulls air into the compost, up the air ducts, throughout the waste pile, and out
the stack. Oxygen in the air reaches the middle of the pile and supports the slow
decomposition process and the treatment of the liquids. Air is also drawn down the
fixtures, especially when a toilet is opened. That oxygen supports the rapid breakdown that takes place at the surface of the pile. The downdraft also prevents odors
from entering the toilet room.
The caretaker sprinkles planer chips (produced as a byproduct by mills that plane
lumber) on top of the pile each day, and turns the pile periodically. That adds bulk,
surface, and keeps the pile “fluffy” so aerobic organisms will grow. Once a month in
the summer, our construction crew adds a commercially produced “bacterium” solution. That is intended to help the naturally growing soil bacteria, mold, and other
organisms thrive. The organisms consume the waste and produce mostly carbon
dioxide (CO2) and water vapor, which is carried away by the draft.
From the user’s point of view, the Clivus works just like an outhouse. However, the
continuous flow of air can sometimes dry the surface of the pile, so there is a danger
of fire from a match or cigarette dropped into the compost chamber. Also, people
may be tempted to use the toilet to dispose of garbage instead of carrying it out.
Signage and the diligence of staff help avoid those problems. We have also found
the unit must be cleaned daily to ensure guest satisfaction as well as proper functioning of the system.
11.4
RANDOLPH MOUNTAIN
CLUB BIO-SUN
COMPOSTING TOILET
By Paul Lachapelle, Volunteer, Green Mountain Club; Doug Mayer, Vice
President and Trails Chairman, Randolph Mountain Club; Anne
Tommaso, former Field Supervisor, Randolph Mountain Club
About the Randolph Mountain Club—Founded in 1910, the Randolph Mountain
Club (RMC) maintains a network of 100 miles of hiking trails and four shelters on
the northern slopes of the Presidential Range on the White Mountain National
Forest in New Hampshire, and on the Crescent Range in the town of Randolph,
New Hampshire. The club has approximately 500 members, and is managed by an
active volunteer board of directors. The RMC is funded by dues and donations from
members, cost-challenge trails contracts with the U.S. Forest Service, and other
state and local grants.
11: CASE STUDIES—BIO-SUN COMPOSTING TOILET—103
RMC’s four shelters consist of two cabins near treeline on Mount Adams: Crag
Camp, with a capacity of twenty, and Gray Knob, with a capacity of ten. There are
also two Adirondack-style shelters, The Perch and The Log Cabin, each with a
capacity of ten. Overnight fees, ranging between $5 and $8, are set to cover the
basic operating expenses of the cabins. The RMC is dedicated to keeping fees as low
as possible.
Two caretakers, based at Gray Knob and Crag Camp, manage the four shelters during the summer. During the rest of the year, one caretaker is in residence at Gray
Knob. The club also has two trail crews, which perform basic maintenance and
erosion control projects. In the summer, a Field Supervisor oversees the caretakers
and trail crews, and acts as a liaison to the Board of Directors.
11.4.1 — HISTORY OF RMC SANITATION EFFORTS
RMC has used several techniques to dispose of human waste. Pit toilets were used at
all camps until visitation began to rise in the 1980s. In 1977, the club had 2,272
visitors among its camps. By 1995, that number had more than doubled to 4,923.
A thermophilic batch composting system, based on methods tested and used at several Appalachian Mountain Club (AMC) and Green Mountain Club (GMC) sites,
was adopted at Crag Camp in the early 1980s. It was satisfactory for a few years, but
required well-trained labor and a large volume of wood chips. Visitors were asked to
not urinate in the toilet, but instead to use the nearby woods. During the ’80s, as
Crag Camp became increasingly popular year-round, the system was eventually overwhelmed.
At Gray Knob, a dehydrating toilet had been installed in the mid 1980s, replacing a
pit toilet. The toilet dehydrated solids while draining untreated blackwater onto
the soil surface. Within a few years, however, the toilet was nearing its capacity, the
system was not adequately dehydrating the solids, and the toilet was serving only as
a collection and storage system. Thus, the RMC faced the prospect of routinely
flying out untreated solids, which would prove expensive and intrusive. Therefore,
the RMC decided a new toilet system was required at Gray Knob.
Evaluation of options—Beginning in 1994, RMC undertook a study of all available
waste management options for its facilities. RMC’s study was headed by Paul
Lachapelle, then a caretaker for the club; options included flying out raw waste via
helicopter, continuing direct burial, propane-fired systems, and thermophilic or mesophilic composters.
The club faced a major challenge: to effectively and affordably manage increasing
volumes of human waste throughout the year, with minimal skilled supervision and
intrusion in the wilderness in a notoriously harsh environment. RMC settled on a
continuous-composting toilet to manage waste on-site because it would eliminate
costly and intrusive helicopter flights and the transport of the large amounts of
wood chips required for a batch-composting system.
Selection of a properly sized composter was critical, since the cold climate allows
composting only between May and September. The remainder of the year, the
composter would function essentially as a containment device.
Continuous-composting toilets (also termed mesophilic systems, because temperatures in the composting pile are lower than in thermophilic systems) operate on the
principle that the waste in the tank, given enough air and time, will decompose into
a soil-like material. Natural oxygen-using bacteria, or aerobes, consume some harm-
104—APPALACHIAN TRAIL CONFERENCE —BACKCOUNTRY SANITATION MANUAL
ful organisms, or pathogens, in the waste. Pathogens are also eradicated over time
when exposed to oxygen, or as a result of the competition between organisms, or the
loss of nutrients and warmth. The volume of the pile is reduced as some of its mass
is converted to carbon dioxide and water vapor by the aerobes. Like any composting
technology, the aim is to optimize conditions for microbial activity.
The essential ingredients of a compost pile are organic material, microorganisms,
moisture, oxygen and heat. The process of transforming raw waste into finished
compost depends primarily on natural soil microorganisms such as bacteria, fungi,
and actinomycetes. Soil invertebrates such as springtails, mites, millipedes, and
beetles also contribute to waste decomposition. Adding wood chips increases the
amount of carbon, absorbs moisture and odors, and provides air space and structure
within the pile. This carbon source (also called bulking agent), preferably hardwood shavings, must be added periodically in order to support aerobic decomposition.
For more information on composting processes, see Section 3—
The Decomposition and Composting Process.
In contrast to thermophilic batch composting, continuous composting is a longterm method that can take years to effectively reduce or eliminate pathogens, and it
requires much less carbon. The compost pile must be regularly mixed to increase
aeration.
RMC decided to install a continuous-composting toilet manufactured by Bio-Sun
Systems of Millerton, Pennsylvania. Although there are numerous commercial
composting toilet manufacturers, this model was chosen for several reasons: First, it
has a large access door to facilitate maintenance of the pile. Second, more air contacts the waste surface, since the waste is suspended on a perforated liner, and air
can circulate below the waste pile as well as above. Lastly, its one-piece tank is made
with 5/16" rib-reinforced, high-density polyethylene, so it is extremely sturdy.
The volume of the tank is 1000 gallons, or 130 cubic feet. The
toilet seat is directly above the sealed tank. A fan powered by a
solar panel in an exhaust vent draws air through the system. During construction, RMC stained the box around the tank black, in
order to increase heat absorption. A thermometer mounted in
the tank monitors the ambient air temperature, and another thermometer in the waste pile records temperatures there.
Installation and modifications of the Bio-Sun toilets—The Crag
Camp Bio-Sun toilet was installed in 1995. Two other Bio-Suns,
at The Perch and Gray Knob, were added over the ensuing three
years. The average cost of the units, including materials, construction, helicopter time, and installation, was $12,000. Funding came primarily from RMC member dues, donations, and overnight fees collected at the facilities. Generous grants from the
Appalachian Trail Conference’s Grant-to-Clubs Program, the
Davis Conservation Foundation, and the Reavis Foundation enabled RMC to bridge a financial gap, and complete the projects.
Figure 11.2—A cutaway view of a Bio-Sun WRS 1000, the model
installed at the Randolph Mountain Club’s Gray Knob Cabin in the
northern Presidential Range of the White Mountains in New Hampshire. Note that the bottom of the tank does not slope. Aged compost must be raked towards the rear access door by the operator,
and newer waste must be pushed forward. Schematic from BioSun Systems, Inc. and the Randolph Mountain Club.
11: CASE STUDIES—BIO-SUN COMPOSTING TOILET—105
During the first year with the Crag Camp Bio-Sun, liquid levels slowly began to
climb in the composter. RMC installed several high-tech solutions to reduce liquid
accumulation, including a “Vapor Core” system, in which a solar-powered motor
spun an impeller that created droplets that could be vaporized in the exhaust stack.
The system worked when installed, but was almost immediately plagued with breakdowns in the harsh mountain environment.
Due to the consequent liquid accumulation, there was minimal aerobic composting,
and anaerobic conditions led to increased odors. The following summer, RMC added
a “beyond-the-bin” liquid treatment system, in which liquids flow out of the
composter into a 55-gallon plastic drum, where they are filtered through alternating
layers of activated charcoal and gravel. The liquid problem was resolved immediately, and the waste started composting. Beyond-the-bin systems were incorporated
into the design of the Bio-Sun toilets when they were subsequently installed at the
Perch in 1996 and at Gray Knob in 1997.
In 1999, RMC added a galvanized-screen drying rack to the process, further refining
the system. The rack enabled caretakers to isolate the end product and finish it on
the rack. In 2000, drying racks were added to the Bio-Suns at The Perch and Gray
Figure 11.3—This is another example of a large, commercially made, continuous
composting system—the Bio-Sun. The model shown here requires more electrical
power than the one in use in the northern Presidential Range of the White Mountains
of New Hampshire by the Randolph Mountain Club, so it may not be practical in many
backcountry situations. Note: This diagram shows two toilet chutes accessing the same
compost chamber. For more information, contact Bio-Sun Systems, Inc. See Commercial Systems in the Contact List in the Appendix.
106—APPALACHIAN TRAIL CONFERENCE —BACKCOUNTRY SANITATION MANUAL
Knob. The design for the racks was taken from the AMC shelter facilities, and has
been fairly effective. Older, composted material is removed from the bin and spread
out on the rack for two to three weeks, depending on the weather. It is then buried
in the woods, 200 feet or more from the cabin.
See contact list in Appendix D.
• NOTE: Many state regulations require burial of finished compost at a depth that
varies from state to state, so check with your local ATC field office and state
agency. Most rules say the material must be buried under six to 12 inches of soil
in a dry, well drained area at least 500 feet from campsites, shelters, trails, and
water supplies.
Because the pathogen content of finished product is seldom checked in the field,
it is always possible that some pathogens survive composting. Therefore, all precautions listed in Chapter TK should be taken when returning compost to the
environment. When selecting a site for burial, always consider all potential contamination avenues, including water, trails, and animal transport to water or
shelters.
Current operation of the Bio-Sun toilet—Two summer caretakers are responsible
for all routine maintenance on the Bio-Suns. The toilets are checked daily to assure
that the solar powered fans are operating and the debris-collecting screen leading to
the beyond-the-bin system is not clogged.
A check sheet is kept in the toilet to keep track of usage. Every twenty-five uses, a
handful of bark chips is added. Any garbage found in the tank is removed and doublebagged. The waste is then packed out of the backcountry, and disposed of in a sanitary landfill.
The pile is mixed once a week. We have yet to find the ideal tool for this task.
Currently, a ten- to twelve-foot-long 2-by-4 seems to work best. Mixing entails knocking down the accumulated cone and thoroughly mixing and aerating the pile. Care
must be taken to keep the older, advanced material to the front of the bin, and the
new, fresh material to the rear.
Packets of bacteria claimed by their sellers to reduce odor and speed composting are
also added once a week. RMC is uncertain how effective they are.
Conclusion—Use of the club’s facilities continues to increase. Overnight visits have
exceeded 5,000 in recent years, and day use has also grown, indicated most visibly
by overflowing trailhead parking areas in the valley. Much of the increase has come
during the colder months, when composting toilets can act only as storage bins, and
by the end of the 1990s use was distributed almost uniformly through the year.
Winter is a challenge for composting toilets. Below 40 degrees F., there is essentially
no biological decomposition. The system must be large enough to accommodate an
entire winter’s accumulation of waste with no reduction in volume until spring,
because it is impractical to remove frozen waste. Winter maintenance consists of
knocking down the frozen cone below the toilet chute and continuing to add bulking agent.
In 1999, overnight visits broke down as follows:
27 percent in Winter (December, January and February)
22 percent in Spring (March, April and May)
23 percent in Summer ( June July and August)
28 percent in Fall (September, October and November).
11: CASE STUDIES—BIO-SUN COMPOSTING TOILET—107
As of 2000, the club had three operating Bio-Suns systems. The Log Cabin, due to
its low use numbers, still had a traditional pit toilet.
Initially, results with the Bio-Sun toilets were mixed. RMC had hoped for a largely
maintenance-free system, but that goal remains elusive, particularly with high usage in
a harsh environment with high humidity, low temperatures and essentially no sunlight.
Following the addition of the beyond-the-bin system and drying racks, the composters
have worked fairly effectively, as long as caretakers check the system regularly. The
screen filter leading to the beyond-the-bin system tends to clog, requiring prompt
cleaning to avoid liquid accumulation. Maintaining a proper chip-to-waste ratio
has also been a challenge, because it is difficult for caretakers to accurately gauge
the usage of the toilets.
Plans include the addition of a mechanical counter to track usage and enable us to
add the correct amount of wood chips. The club also hopes to experiment with the
addition of red wiggler worms to speed composting.
Finally, the RMC hopes to test the material for pathogens to determine whether it
could be spread on the forest floor, reducing the environmental impact and labor of
burying waste.
11.4.2 — GRAY KNOB: A COLD, DARK PLACE
Welcome to the Randolph Mountain Club’s Gray Knob cabin—Nestled under a
craggy outcrop of rocks, at treeline at 4,481 feet on the side of Mount Adams, RMC’s
Gray Knob cabin is the only enclosed structure in the Presidential Range open to
the public year-round. The Gray Knob caretaker welcomes an assortment of overnight hikers, day hikers, climbers and even die-hard backcountry skiers, all headed
Figure 11.4 The Randolph Mountain Club’s Gray Knob Cabin in the northern Presidential Range of the White Mountains in New Hampshire. Drawing by Eric Scharnberg,
from the Randolph Mountain Club.
Figure 11. 4— Imagine trying to compost in a remote location with an average temperature of 36 degrees Fahrenheit, fog 270 days annually, a northern exposure with
no direct sunlight for more than a month every year, and its highest usage in mid-
108—APPALACHIAN TRAIL CONFERENCE —BACKCOUNTRY SANITATION MANUAL
up Mount Adams. Just 1.3 miles off the Appalachian Trail, the cabin is also frequently used by thru-hikers seeking refuge from the wild weather of the Presidentials.
In 1999, Gray Knob had nearly 2,000 overnight guests, and at least as many dayhikers—most of whom eventually find their way to the Bio-Sun toilet.
Using the knowledge the club gained from installing and operating Bio-Sun toilets
at Crag Camp and The Perch, a Bio-Sun was added to Gray Knob in the fall of
1998. Funding came from Gray Knob overnight fees, RMC members, donations,
and a generous grant from ATC.
The system uses a beyond-the-bin liquid filtration system. A solar panel powers an electric fan in the exhaust stack, removing odors from the toilet, and moving moistureabsorbing fresh air over the waste pile. Atop the exhaust stack, a passive, venturi-effect
cap (which uses wind to create suction) adds to the draft created by the fan.
From late September through early May, the toilet is essentially a containment bin,
with little or no composting. During these frigid winter months, the only maintenance is the dreaded “knocking down the cone.” When May arrives, however, the
caretaker literally has his or her hands full, with composting in full swing. A drying
rack is used to isolate and finish the end product.
For more information, please refer
to the contact list in Appendix D for
RMC and ATC addresses.
So—how’s it going? As of 2000, pretty well. Come up on Lowes Path and see for
yourself. And if the urge strikes, make your contribution to our composting workin-progress.
11.5
AT HOME WITH THE
CLIVUS MULTRUM
By Richard Andrews, Volunteer, Green Mountain Club
The Clivus Multrum is a commercially manufactured, self-contained, continuouscomposting toilet. It relies on mesophilic, or low-temperature, composting, which
some people call moldering to indicate that it takes place with no significant temperature rise. Developed in Sweden, the design was licensed to Clivus Multrum
USA for manufacture and sale in this country in the early 1970s.
I have had extensive experience with the Clivus Multrum, since I installed the fifth
one manufactured in the United States (serial #005) in my home in 1974, and have
used it continuously since. I also sold Clivus Multrums for several years, and have
observed many installations, both successes and failures.
Although the Clivus Multrum has worked well for me, I consider it unsuitable for
most backcountry situations. Of course, its shortcomings in the backcountry also
apply to some degree to all composting toilets that resemble it.
At several thousand dollars a unit, the Clivus Multrum is too expensive for many
backcountry situations. More important, it must be sheltered from the weather, and
it requires warm temperatures to have reasonable capacity. The rate of activity of
the decomposing organisms in a Clivus Multrum approximately doubles with each
20-degree Fahrenheit increase in temperature. Thus, the capacity of a Clivus Multrum
doubles from 40 degrees Fahrenheit to 60 degrees, and doubles again from 60 to 80
degrees. The building required to shelter and warm a Clivus Multrum multiplies the
cost of an installation. Insulation alone cannot provide warmth, because the decomposition process creates insignificant heat.
11: CASE STUDIES—AT HOME WITH THE CLIVUS MULTRUM—109
Although the designers of the system intended it to evaporate all liquid, in practice
this happens only under ideal conditions, such as installations in the warm and dry
climate in the American Southwest. In most other places, evaporation is less complete, so liquid accumulates in the bottom of the tank, and must be dealt with.
Since a Clivus Multrum composting tank is an impervious container, the system
requires a good draft in its ventilation stack to work properly, and this is often difficult to ensure in the backcountry. The composting tank is bulky and hard to transport. Finally, if users ignore instructions and introduce trash, it is difficult to reach
and remove.
Design of the Clivus Multrum—The Clivus Multrum is a large (approximately
four feet wide by ten feet long by seven feet tall in our case) fiberglass-reinforced
resin tank with a bottom sloping at 30 degrees. Early versions of the tank were not
insulated, but modern versions include a layer of foam plastic insulation to conserve
warmth. However, material that can be biologically metabolized to produce heat is
introduced into continuous composting toilets at a low rate, so the generation of
heat occurs at a low rate. In addition, the minimal heat of decomposition is steadily
removed by evaporation and ventilation. As a result, there would be no significant
temperature rise even if the tank were perfectly insulated, and this insulation is of
questionable value.
Air channels built into the tank ensure that no part of the compost pile is far from
air. A vertical chute connects to a toilet seat on a floor above the highest portion of
the tank. A bulking agent, such as wood shavings, is added through the toilet chute
regularly to keep the pile aerobic. A vent with a fan removes odors, water vapor and
other gases produced by composting, such as low concentrations of carbon dioxide
(and methane and ammonia if parts of the pile become anaerobic). A second vertical chute may be included for food waste in homes where the kitchen is conveniently located.
The tank must be placed on a platform sloping at 30 degrees, an angle intended by
designers to cause compost to tumble in slow motion toward a cleanout door above the
lowest portion of the tank. Most users find that the compost does not move by itself, but
the slope does make it easier to pull compost toward the cleanout door for removal.
Water that does not evaporate and dissolved solids collect in the bottom of the
tank, and must be drained or pumped periodically. Since some evaporation does
take place even under unfavorable conditions, the liquid is a concentrated solution
of the salts contained in urine, plus whatever else is leached out of the compost pile.
Research by Clivus Multrum indicates that the liquid is bacteriologically benign as
long as it has percolated slowly through aerobic portions of the compost pile, and
the company says that lack of odor in the liquid indicates it is stable and has been
adequately treated. This is only possible if use of the toilet does not exceed its capacity. Since use levels may exceed capacity without continuous monitoring and
control, it is generally considered wise to handle the liquid as if it were black water
(untreated sewage).
Small portions of the compost pile in a Clivus Multrum may become anaerobic from
time to time. This is not considered a problem as long as most of the pile is aerobic,
because material will generally move out of the anaerobic region into aerobic conditions, where pathogens will be attacked and largely eliminated.
Clivus Multrum has arranged for analysis of compost produced by its composting
toilets. The results indicate that elimination of pathogens is not perfect, but the
concentration of pathogens in the finished product is comparable to that in typical
soil. Blind bacteriological tests cannot distinguish the compost produced by a properly functioning Clivus Multrum from a soil sample.
110—APPALACHIAN TRAIL CONFERENCE —BACKCOUNTRY SANITATION MANUAL
Flies are sometimes a problem, especially in a new installation in which a balanced
ecosystem has not established itself. Once a Clivus Multrum is working properly,
soil invertebrates consume fly eggs before they can hatch, although the predators
may occasionally fall behind if a lot of food waste contaminated by fly eggs is introduced at once. Flies may also be a problem if the surface of the compost gets too dry,
which can be cured by occasional light spraying with water.
Our experience—My wife and I installed our Clivus Multrum in 1974, 26 years ago.
It has been used by an average of two people. Our house has sometimes been vacant
for a month or two, but we also have visitors, and occasionally as many as three
other people have lived with us for several months at a time. Often the house is
occupied all day, while most overnight backcountry sites are vacant much of the
day—and 24-hour occupation produces more human waste than a simple overnight.
Thus, our average usage has been equivalent to a campsite with a use level of 800 to
1,000 overnights annually.
The toilet and food waste chutes are on the first floor of the house. The composting
tank is in an unheated basement. We had no electricity other than that provided by
a small wind generator for fifteen years, and the temperature in the basement varied
between 34 degrees F. in midwinter and 58 degrees F. in midsummer. Clivus Multrum
said the composting tank should be in a space averaging at least 60 degrees F., a
temperature our basement never even reached for that first fifteen years. An average annual temperature of 60 degrees or more will not be reached outdoors in the
backcountry except in the warmest locations. However, since our tank was sized for
continuous use by four people, the composting process worked fast enough to keep
up with input. In mesophilic composting, time, warmth and volume can substitute
for each other.
Clivus Multrum said a fan in the vent stack was essential, but with such a small
supply of electricity, natural ventilation was our only possibility. I installed a
stack reaching the peak of our story-and-a-half house, giving a vertical rise of
about twenty-three feet from the top of the composting tank. This provided
excellent draft in winter, when the basement air was warmer than the outdoors,
but little or no draft in summer, when the basement was cooler than the outdoors. Yet in midsummer the basement was as warm as it would get, so the
composting process would be at its annual peak, requiring the maximum supply
of air. Something had to be done.
I installed a rotating turbine ventilator designed to enhance draft from wind, which
worked well in summer. But water vapor from the tank formed unbalanced accumulations of ice on the turbine in the winter, causing a terrible racket when the wind
came up. Our house is on an exposed location at an elevation of 2,000 feet, and the
climate was colder twenty-five years ago than it is now, so ice accumulated for long
periods: we experienced intervals as long as three weeks of subzero weather, with
almost constant wind, and periods of windy subfreezing weather much longer than
that. A stationary draft-enhancing chimney cap was quieter, but ice still formed in
the downwind portions of the cap, eventually plugging the exhaust route. When
this happened, the wind drove through the open upwind passages of the vent cap
and down the vent stack, reversing the draft, chilling the composting tank and
forcing odors into the house. The only cure was to plug the vent stack until a thaw
arrived. This caused no problem, because the composting process was largely dormant in such chilly conditions, so it required next to no air.
After fifteen years, we connected to the electric grid. This made it possible for us to
have running water and a water heater. As a result of the water heater and a warmer
climate, the basement is now 10 degrees F. warmer throughout the year than it was.
I vented the propane-fired water heater into the Clivus Multrum vent stack, which
11: CASE STUDIES—AT HOME WITH THE CLIVUS MULTRUM—111
warms the stack and provides draft for reliable ventilation in summer, and also prevents ice accumulations in the vent cap in winter.
In the first couple of years we had the Clivus Multrum, flies were occasionally a
problem. A few times they got so bad that I reluctantly hung pesticide strips above
the compost pile in the tank. As biological activity in the compost pile increased
and became more diverse, flies became less of a problem. The surface of the compost
pile is now a seething busyness of sowbugs, rotifers and other composter’s helpers.
Flies are also controlled by using ample bulking agent and keeping the surface of the
compost pile moist, which I do by spraying it with a little water once a week. The
tank produced some moths when we went on a two-month vacation in the very dry
summer of 1999, but they were gone within a week of thoroughly wetting the pile
upon our return.
Liquid has always accumulated in the lower end of the composting tank. In the
early years, I bailed it, carried it outdoors in buckets, and poured it on the lawn. For
a while I installed a hand-powered bilge pump sold by Clivus Multrum to transfer
the liquid into buckets, but it plugged easily, and soon broke. When we got electricity, I bought an electric sump-and-bilge pump that can handle salt water, installed it
in the tank, and piped the liquid into our septic tank, which disposes of gray water
from our sinks, shower and washing machine. I operate the pump once a week, and
it has worked well since its installation. We no longer garden, because our nextdoor neighbor has poor fences and livestock that devour a garden in fewer than five
minutes, but acquaintances who do garden sometimes ask for jugs of “Clivus tea,”
which they say is a super fertilizer.
We have tried various bulking agents: partially rotted leaves from the forest floor,
sawdust, and pine shavings. Leaves tend to form mats, and sawdust also tends to
compact. The same is reported of grass clippings, hay and straw. Pine shavings have
been the best of the things we have tried, remaining comparatively loose and aerated even when wet. We add about one quart per day of pine shavings, so a ninecubic-foot bale, costing $3, lasts nine months. The shavings also are fragrant and
not objectionable even if some spill on the bathroom floor. Some owners of Clivus
Multrums use peat moss as a bulking agent, but I have had no experience with it.
Some composters find hardwood shavings better than softwood, but pine shavings
have worked for us, and they are available locally at agricultural supply stores, which
sell them as bedding for livestock.
In the early years, I removed compost through the clean-out door once a year or
once every other year. The material is, as Clivus Multrum advertises, brown, crumbly and odorless. Peach pits and fragments of bone survive composting, but eggshells, corncobs, peanut shells and toilet paper vanish. I have disposed of the compost by dumping it in our fifteen acres of woods. I did not keep good records of the
amount of compost produced, but I typically removed six five-gallon buckets in a
cleaning.
In 1992, I bought a pound of red wiggler worms (also called redworms or manure
worms) and put them in the Clivus Multrum. In addition to consuming organic
material themselves, the worms aerate and mix the pile, and carry fungus spores and
other micro-organisms around the pile. They have made a remarkable difference. In
fact, I have not removed any material from the compost tank in the eight years
since I introduced the worms. I keep telling myself I ought to get around to it, but
the pile has not reached a crisis point.
Despite the slope of the bottom of the tank, material does not move from the top of
the tank to the lower end by itself. It builds up beneath the toilet chute, and about
once a month I use a long stick to shove fresh material down into the lower portion
112—APPALACHIAN TRAIL CONFERENCE —BACKCOUNTRY SANITATION MANUAL
of the tank. This would probably be a less frequent chore if I removed some of the
compost from the lower end of the tank, thereby increasing the slope of the top
surface of the pile. But shoving material with a stick is less work than removing
compost, so human inertia wins, and the status quo endures.
11.6
AIRLIFT HAUL-OUT
SYSTEM
By Chris Thayer, Huts Manager, Appalachian Mountain Club
The Appalachian Mountain Club (AMC) still uses an airlift haul-out barrel method
of waste management at Zealand Falls and Greenleaf Huts in the White Mountains
in New Hampshire. AMC’s eight huts, spaced about a day’s hike apart, are located
near or above timberline, where there is little or no soil. The White Mountains
have such a severe climate that they have pockets of permafrost and have recorded
the world’s highest surface wind velocity. The staffed and fully enclosed huts provide meals and bunkroom-style shelter for 36 to 90 people.
Haul-out systems evolved from predecessors such as cesspools and pit toilets, and
came about through recognition that use levels at our high-elevation huts were too
high for the old methods. We hope to phase out these systems soon, because, although they are simple and the cheapest to install in the short term, with initial
cost of about $10,000 to $20,000 per hut, maintenance expenses rise as the numbers
of users increase.
In our haul-out systems, waste is airlifted to a local sewage plant, where it is treated
for a fee. The caretaker, the primary maintainer of the system, keeps a close eye on
levels in the barrels, winches them out of the iron holding vaults when full, caps
them, and removes them from the hut to a holding field until airlift, replacing them
in the holding vaults with empty barrels.
Maintenance includes buying and retrofitting suitable barrels and buying equipment for safe removal of barrels. A good relationship with a local treatment facility
is essential. It is important to keep seasonal vegetation trimmed in the area to facilitate the loading and storage of waste barrels and for safe airlift operations. The
ground must be kept level to prevent barrels falling over, especially in winter. In
winter the caretakers must keep the loading and storage area shoveled so that when
the snow melts and thaws, it doesn’t cause the barrels to fall over. Caretakers must
monitor each barrel for leaks or other signs of weakness, so they can be replaced
when necessary.
11.7
FLUSH TOILETS WITH
LEACH FIELD AT HIGH
MOUNTAIN HUTS
By Chris Thayer, Huts Manager, Appalachian Mountain Club
Two of the highest huts maintained by the Appalachian Mountain Club (AMC),
Lakes of the Clouds Hut (5,012 feet) and Madison Spring Hut (4,825 feet), use
flush toilets with leach fields. The AMC’s eight huts, spaced about a day’s hike
apart, are located near or above timberline, where there is little or no soil. The
White Mountains have such a severe climate that they have pockets of permafrost
11: CASE STUDIES—FLUSH TOILETS WITH LEACH FIELD—113
and have recorded the world’s highest surface wind velocity. The staffed and fully
enclosed huts provide meals and bunkroom-style shelter for thirty-six to ninety
people.
The cost of implementing these systems over a period of years has been estimated at $80,000 for each hut. Lakes of the Clouds Hut has eight toilets, and
Madison Spring Hut has four. Each system has low-flow toilets that empty into
a feces-separator strainer, which separates and retains solids from the waste water, and allows liquids to continue through the system. The strainer keeps the
majority of the solids from entering the septic tank, so the tank doesn’t have to
be serviced as often, and it allows solids to dry completely, making them lighter
and much less costly to airlift out.
After the strainer, wastewater goes to a septic tank, where more solids are separated.
Some float on the surface and are held back by baffles in the tank, and other solids
sink to the bottom. Active and significant bacterial decomposition also takes place.
The tank has an automatic doser to insure that all portions of the leach field are
used. When the appropriate water level is reached in the tank, the doser dumps the
contents of the tank onto the leach field.
Figure 11.5—Map of the Appalachian Mountain Club’s Lakes of the Clouds Hut on the
A.T. in the White Mountains of New Hampshire. From the Appalachian Mountain Club.
114—APPALACHIAN TRAIL CONFERENCE —BACKCOUNTRY SANITATION MANUAL
Our first leach fields were filled with sand, but new ones use black anthracite coal
flakes instead. The grains of coal are more uniform in size and offer more surface
area per grain, and coal is much lighter to airlift in to the location. The wastewater
is sprayed on the top of the field, and as the water settles through the filtering medium, the remaining solids are removed. Pick-up pipes in the bottom of the leach
field gather the filtered, treated water and carry it on down the system. Bacterial
decomposition is active and important here also.
The final disposal system, which discharges the treated water, varies system by system. Some use plain perforated pipe; others use a chlorinator, doser (manual or
automatic), and perforated pipe to disperse the liquid into the soil.
Cleanliness of the toilet area and the rest of the system, and diligence in maintenance, are essential. Every day, the caretaker cleans the system and walks the entire
line to ensure function and integrity. Annual maintenance by our construction crew
includes periodic changing of the septic field leaching materials (we typically change
an inch or two of filter material each year) and close monitoring of every component, including the amount of water used and the quality of the discharge.
Solids also must be shoveled from the septic tank at the start of each season and once
midway through the season, for removal and disposal at a sewage treatment plant.
Figure 11.6—Map of the Appalachian Mountain Club’s Madison Spring Hut on the A.T.
in the White Mountains of New Hampshire. From the Appalachian Mountain Club.
11C
:ASSETUDES—
I WOODF
-REIDCOMPON
ISTCNIERATOR—115
11.8
By Richard Andrews, Volunteer, Green Mountain Club
Some jurisdictions do not allow composted human waste to be applied to land. In
those places, the product of composting systems must be removed from a site. Unfortunately, that requirement offsets much of the potential advantage of treating
human waste by composting at backcountry sites. To make composting useful while
meeting such requirements, incineration of compost is an obvious possibility. No
pathogen could survive combustion at high temperatures. Many biological nutrients would be destroyed as well, and if the remaining ones were a concern, a small
amount of dry ash is much easier to transport away from a backcountry site than a
large amount of damp compost.
Incineration of human waste has been done at some backcountry sites, particularly
at heavily used sites in the West. However, manufactured incinerators are expensive and intrusive, and require large amounts of liquefied petroleum fuel (propane
or butane), which is a continuing expense, a questionable use of a nonrenewable
resource, and a transportation and aesthetic headache. Reports indicate the incinerators can be smelly as well, although this objection would probably disappear if an
incinerator were used for compost rather than fresh sewage.
In contrast, a practical wood-fired incinerator is an appealing prospect for forested
backcountry sites in the East, where modest or even ample amounts of downed
wood are often available nearby—especially if the incinerator can use damp or green
wood.
In the fall of 2000, I built an inexpensive, lightweight prototype compost incinerator that successfully burned compost from my household Clivus Multrum composting
toilet, using green wood as the supplementary fuel. Except for a short time immediately after ignition, the smoke was either invisible or largely steam, indicating reasonably clean combustion. The product was a fine, white ash. Even bones could be
crumbled to white powder between one’s fingers after going through the incinerator
(the Clivus Multrum composts kitchen garbage as well as human waste). The cost
of materials for the prototype was about $30.
However, the prototype was not problem-free. The chief difficulty was that compost
and wood sometimes jammed in the vertical, gravity-feed fuel magazine. A tapered
fuel magazine, wider at the bottom than at the top, would probably solve this problem—but only further testing can confirm this guess. It might also be solved by
using wood chunks of a different shape as supplementary fuel.
The incinerator also must be scaled up to a larger size than the prototype, which was
too small to be practical in the field. However, that is unlikely to be a problem,
since the chief goal is high-temperature combustion, which is easier to achieve in a
large fire than a small one.
The incinerator consisted of three concentric lengths of stovepipe. The combustion
chamber was two two-foot sections of eight-inch diameter pipe (four feet long overall), standing vertically and stayed with three guy wires to prevent tipping over. Air
inlets with a total area of about ten square inches were cut in the sides at the bottom, and a woven wire grate was installed six inches above the bottom.
One section of ten-inch diameter pipe (two feet long) stood outside the combustion
chamber, so incoming air had to travel down through the one-inch space between
PROTOTYPE WOOD-FIRED
COMPOST INCINERATOR,
APRIL 2001
116—APPALACHIAN TRAIL CONFERENCE —BACKCOUNTRY SANITATION MANUAL
the two pipes before entering the air inlets in the combustion chamber. That preheated the combustion air and reduced heat losses from the combustion chamber,
creating a very hot fire on the grate.
A four-foot length of six-inch stovepipe was suspended centered in the combustion
chamber, with the bottom six inches above the grate. That was the fuel magazine.
To use the incinerator, I dropped wads of crumpled paper down the fuel magazine
until it was about half full, and then dropped in a flaming wad of paper, followed by
dry kindling and then a few sticks of dry wood, cut to a length of about three inches.
Once that was burning well, I followed it by dropping in sticks of green wood, also
about three inches long. Once a good fire was established, I scooped in a fuel mixture consisting of equal weights of green wood chunks and damp compost. That
mixture fed by gravity into the fire as fuel burned away on the grate at the bottom.
Ash fell through the grate onto the ground below. After I stopped adding fuel, the
fire burned until the fuel was consumed—as long as the wood-and-compost mixture
did not hang up, or jam, in the fuel magazine.
Smoke from the fire traveled up through the one-inch annular space between the
fuel magazine and the combustion chamber. Thus, the fuel magazine was surrounded
by hot stack gases, which partially dried and preheated the compost-fuel mix before
it reached the fire. I covered the top of the fuel magazine with a small piece of sheet
steel to prevent smoke from smoldering portions of the fuel load from escaping without going through the hottest part of the fire.
After the snow melts, I intend to build and test a larger prototype. For information
on the progress of those experiments, contact the Green Mountain Club.
12
The Decision-Making Process
Pete Ketcham, Field Supervisor, Green Mountain Club
J.T. Horn, New England Regional Representative, Appalachian Trail
Conference
Chris Thayer, Huts Manager, Appalachian Mountain Club
Paul Neubauer, former Field Supervisor, Green Mountain Club
This chapter has three portions.
• Section 12.1 is a general discussion of the process of determining the best option
for disposal of human waste at a backcountry site.
• Section 12.2 is a case study showing how a particular consideration—the feasibility of depending on volunteers for operating a demanding sanitation system—
affects the choice of a system.
• Finally, Section 12.3 is a matrix listing the characteristics of various backcountry
sanitation systems. The matrix is intended as a systematic guide to deciding which
system is best for your site.
12.1
The decision to provide sanitation facilities at a backcountry campsite is a major
one for Trail maintainers, clubs and land-managing agencies. Providing sanitation
facilities requires a substantial expenditure of time and resources, both financial
and human, for maintenance during the life of the system as well as for its planning
and installation.
DETERMINING THE BEST
OPTION
118—APPALACHIAN TRAIL CONFERENCE —BACKCOUNTRY SANITATION MANUAL
The challenge is to choose which system best balances the needs and limitations of
the site, the needs and limitations of the maintaining organization, and any related
impacts.
Sites for advanced sanitation systems—Any site where wastes accumulate faster
than they break down in catholes or pit privies is a candidate for an enhanced backcountry sanitation system. The site must be able to absorb wastes left by hikers and
campers, or wastes must be removed from the site, to ensure that the natural resource is not damaged and public health and safety are not compromised.
An enhanced sanitation system is recommended for sites that receive more than
about ten overnight visitors per week, or the equivalent, and that have any of the
following conditions:
1. Soils that are shallow (less than four feet to bedrock, hardpan or seasonal high
water table).
2. Soil that is poorly drained—that is, it is fine textured (such as silt or clay) or a bog
soil.
3. A location that is closer than 200 feet to ponds or streams.
An enhanced backcountry sanitation system may also be advisable for sites where
soils are adequate for pit privies, but use is high enough that pits are filled and the
toilet is moved frequently, and where the number of pits threatens groundwater—or
where it is becoming difficult to find unused sites for pits.
Advanced backcountry sanitation systems are unnecessary if use is very low (less
than 100 persons per season). A simple enhanced system, such as a moldering toilet,
could succeed with attention only once or twice a year. However, it is inadvisable to
attempt a more complex sanitation system without enough volunteers or field personnel to operate the system. Some enhanced systems require maintenance at least
two times a month, unless usage is very low. Weekly or even daily attention may be
required with some systems at high- to very high-use day and overnight sites.
Site Examination—A site must first be evaluated to consider access to the site,
placement of facilities, suitability for handling of sewage and compost and for storage of bulking agent, tools, and other items, and for its capacity to absorb finished
compost with acceptable impact.
Examine and map the surface water flow on the site, and try to identify subsurface
flows. Identify areas suitable for spreading composted sewage.
Topography may limit where you can put certain kinds of toilets, and that may
influence or determine which type of system is appropriate. Toilets should be as far
from the water source as possible, which dictates siting them in the opposite direction from water. System components should be near but behind the outhouse, so
hikers will not have to walk past composting operations to use the privy.
If the site is wet, the outhouse and any components should be placed on platforms.
A consistently wet site precludes some systems, particularly a moldering privy. The
area should be ditched to direct surface and shallow subsurface flows around and
away from installations such as an outhouse, bin, and storage platform. The trail to
the outhouse should be hardened, and large flat rocks or other firm surfaces should
be provided for mainteners to stand on while working on the system.
12: THE DECISION MAKING PROCESS—119
12.2
By Paul Neubauer, former Field Supervisor, Green Mountain Club
On the Appalachian Trail in southern Vermont, the Brattleboro Section of the
Green Mountain Club (a section is a semiautonomous chapter of the club) maintains a batch-bin composting system at Spruce Peak Shelter. The section has managed to maintain the system, but it has been a challenge. Another club considering
installing a demanding sanitation system should consider carefully whether its members are up to the job.
The arrangement at Spruce Peak Shelter could be replicated elsewhere on the A.T.,
especially where ridgerunners employed by the Appalachian Trail Conference (ATC)
or the land-management agency patrol nearby. The Mountain Club of Maryland
and the Blue Mountain Eagle Climbing Club in Pennsylvania have established such
relationships to maintain batch-bin and Clivus Minimus composting systems.
Spruce Peak shelter has become increasingly popular with both thru-hikers and
day- hikers, so the sewage volume has surged. To cope with this, GMC’s field staff
helped the section install a 70-gallon catcher in the outhouse to avoid overflows
when the volunteer operator can’t get to the site frequently. The section cooperates
with GMC’s seasonal field staff, which is stationed nearby, to ensure that the batchbin system is checked and serviced properly.
This experience has shown that getting a system up and running is daunting for a
volunteer group, partly because most of the members generally do not have prior
experience with such installations. After installation, it is a major group effort to
maintain the structures and transport the bulking agent (bark, shavings, and/or other
materials).
However, if no major repair work is required and there is storage for a large stockpile
of bulking agents to accommodate the irregular availability of volunteers, a batchbin composting system can be maintained by a dedicated individual volunteer or
group, provided use of the site does not exceed 100-150 overnights per season. There
also must be a large catcher in the privy and reasonable access to the site.
The big challenge comes when a batch of compost is being run through the process,
and the pile should be turned every three to five days. If a maintainer cannot visit
the site regularly during a run, he or she must allow more composting time to assure
effective treatment of the sewage. This may require ample storage capacity to accumulate sewage awaiting the next run.
Turning at longer intervals increases the chance that some sewage will not be subjected to a sufficient period of high temperatures. However, if a system at a low- to
medium-use campsite is well-managed, lengthening the compost run period and
increasing the time the compost is retained on drying racks can compensate for this.
Of course, volunteer operation of a batch-bin composting system is impossible if a
club chooses to prohibit volunteers from handling sewage.
CASE STUDY: THE ROLE
OF VOLUNTEERS AND
FIELD STAFF IN MAINTENANCE OF A REMOTE
BATCH-BIN COMPOSTING
SYSTEM ON VERMONT’S
LONG TRAIL
120—APPALACHIAN TRAIL CONFERENCE —BACKCOUNTRY SANITATION MANUAL
12.3
BACKCOUNTRY
SANITATION SYSTEM
DECISION MATRIX
Definition of terms—The matrix on pages TK-TK is a guide to the process of deciding which sanitation system is suitable for a backcountry site. Each system is
discussed according to the following terms:
Principle at work—The biological process operating in the system. See Section 3
of this manual, “The Decomposition Process.” On the A.T. there are two types of
anaerobic systems, four types of low-temperature aerobic systems (moldering, or
slow composting), and types two-high temperature aerobic systems (thermophilic,
or rapid composting).
Site preferences—Topographical and other site factors affecting the choice of system: size, slope, ground type (e.g. ledge or boulders) and moisture content, tree
cover, orientation requirements (e.g. facing south), road access. See Section 3 of
this manual, “The Decomposition Process,” along with Sections 7-11 and the
listings of clubs and manufacturers in the Appendix.
Environmental limitations—Limiting weather conditions, soil qualities, or energy
requirements such as wind or sun. See Sections 7-11 of this manual, and the listings of clubs and manufacturers in the Appendix (except for Pit Privy, Vault Toilet, and Penn. Composter).
Level of use tolerated—System capacity, the factors that affect it, and how system
effectiveness may change with increasing use. See Sections 7-11 of this manual,
and the listings of clubs and manufacturers in the Appendix.
Breakdown process—The effect of the principle at work on the system’s operation.
For example, whether the system requires a short or long retention time of
composting material. See Section 3 of this manual, “The Decomposition Process.”
Regulatory issues—Permits and environmental assessments (e.g., National Environmental Protection Act (NEPA)) required by local, state, and federal authorities; approvals required from local clubs, land managers and ATC. See Section 5
of this manual, “The Regulatory Process.”
Sanitation issues—Risks of contamination to the operator, the hiking public, and
the area’s natural resources. Tolerance for error in operation. Requirements for
handling raw material and removing finished material. See Section 4 of this manual,
“Health and Safety.”
Aesthetic issues—Impacts of the system on the experience of site visitors. See Section 6 of this manual, “Aesthetic Issues.”
Installation issues—Complexity of installation and skills required. Transportation
requirements (such as helicopter, truck, pack stock, backpacking). Structures required for housing components. Auxiliary components, such as a liquid management system or drying rack. See Sections 7-11 of this manual, and the listing of
clubs and manufacturers in the Appendix.
Cost of installation—The basic cost of the components of each system. Additional
costs of permits, labor, transportation and construction also must be considered.
See Sections 7-11 of this manual, and the listing of clubs and manufacturers in
the Appendix.
12: THE DECISION MAKING PROCESS—121
Labor for installation—Requirements for paid and volunteer labor for installation
of the system. See Sections 7-11 of this manual, and the listing of clubs and manufacturers in the Appendix.
Operation issues—Frequency and type of attention required. See Sections 7-11 of
this manual, and the listing of clubs and manufacturers in the Appendix.
Cost of operation—The daily, weekly, monthly, and yearly costs. These might include additives, biological accelerants (e.g., enzymes or red worms), and bulking
agents (e.g., bark mulch, shavings or duff); energy (e.g., solar systems or batteries);
and replacement parts (e.g., fans, mixing blades, pumps, etc.). See Sections 7-11
of this manual, and the listing of clubs and manufacturers in the Appendix.
Labor for operation—Requirements for paid and volunteer labor for operation; need
for a service provider from the manufacturer of the system. See Sections 7-11 of
this manual, and the listing of clubs and manufacturers in the Appendix.
122—APPALACHIAN TRAIL CONFERENCE —BACKCOUNTRY SANITATION MANUAL
Decision Matrix
Pit Toilet—Standard pit privy, not detailed elsewhere in
this manual.
Installation issues—Basic carpentry is needed. Requires
transportation of materials to site, digging a substantial
pit.
Installation costs—From $200-$600 in lumber and supplies.
Principle at work—Dig as deep a hole in the ground as
possible. However, the bottom of the pit should be 18-20”
above the seasonal high for the water table. Some states
may have regulations regarding pit construction, check
with your ATC regional office. Then mount a simple structure on top. Waste collects in the pit. When the pit fills,
the privy is moved and the hole is covered. Pathogens
take years to be destroyed, the principle in effect is the
amount of time pathogens are exposed to unfavorable conditions
Site preferences—A dry site in which to dig the pit, with
deep soils and a low water table.
Environmental limitations—Environmental factors that
challenge use: Little or no soil, a ledge, a high water table,
soils that don’t drain well, and steep slopes; extreme cold
(where the average mean temperature never gets above
40 degrees Fahrenheit; clay soils that do not drain at all.
Level of use tolerated—Varies with size of pit and levels of
use. Climate influences the rate at which wastes decompose. The higher you go, the colder and wetter the climate, and the slower the decomposition. Every 1,000 feet
in elevation gained means it will be 3 to 5 degrees Fahrenheit cooler. Climate will vary with the elevation of your
site, latitude, and other factors.
Installation labor—Two to three days of labor to build the
structure. A day’s work to dig the pit. Transportation to
the site.
Operation issues—Must be well vented and screened to prevent odor and flies.
Operation costs—Free. Except for labor to move periodically and for repairs/replacement with regards to the structure.
Operation labor—Privy must be moved periodically. The
size of the pit and the frequency of use determine the need
to move pit.
Vault Toilet—Standard container-style toilet, not detailed
elsewhere in this manual.
Principle at work—Waste goes into a sealed vault made of
concrete or other impervious material. Waste is pumped
out when full. Pathogen reduction is achieved by “treatment” of the effluent at a municipal sewage treatment
plant.
Breakdown process—Anaerobic and malodorous. Slow
breakdown in pit that may take decades to fully decompose.
Site preferences—Road access is required. Other possibilities could be the removal of waste from vaults with aircraft or ATV. Those two would require a trail or clearing
of an area for landing a helicopter.
Regulatory issues—Some states do not permit pit toilets.
The USDA Forest Service and National Park Service must
comply with NEPA.
Environmental limitations—Environmental factors that
challenge use: ledges and steep slopes; could require major excavation and blasting to overcome those limitations.
Sanitation issues—May cause ground water contamination. Pits must be closed when waste reaches within one
foot of the original grade. Pits must be properly capped
with three to four feet of soil when full. There is some
tolerance for error in operation.
Level of use tolerated—High, depending on use levels, size
of vault, and frequency of cleaning.
Aesthetic issues—Can have unpleasant odors if not vented
properly. Flies and vermin are possible if not maintained
well.
Regulatory issues—Must be an approved design. Federal
agencies must comply with NEPA.
Breakdown process—None. Waste is removed and disposed
of regularly.
Sanitation issues—Should be an approved design that is
totally contained.
12: THE DECISION MAKING PROCESS—123
Aesthetic issues—A substantial structure that may be intrusive in backcountry. Requires road access.
Installation issues—Heavy equipment is required to dig hole
and install tank.
Installation costs—Several thousand dollars.
Installation labor—Must be done by contractor with experience and heavy equipment.
Operation issues—Must be well vented to prevent odors.
Regular pumping must be scheduled.
Operation costs—Must be pumped regularly. Several hundred dollars each time.
Operation labor—Routine pumping by a licensed septic
hauler.
Regulatory issues—System remains experimental: Has been
approved for where it has been implemented. Check with
the appropriate land manager and ATC regional office before installing.
Sanitation issues—Crib must be constructed properly to ensure adequate and safe operation since it is an aboveground system. The number of cribs needed will depend
on use levels; you will need at least two. The goal is to
have enough storage capacity to allow a long retention
time for the waste in the crib—six months to a year is
ideal. Having enough storage minimizes the amount of
handling of the material and ensures the greatest level of
pathogen reduction. An alternative to ensure maximum
pathogen reduction would be to have finished material
sit on a drying screen for up to a year. Health hazard to
the maintainer is a potential risk. There is some tolerance to error in operation.
Aesthetic issues—Few. If you build multiple cribs, the area
can become more cluttered in appearance.
Mouldering Privy—Described in Section 8 of this manual.
Principle at work—An above-ground chamber (crib) is constructed to collect the waste. Liquids drain through the
pile and into the soil, thus allowing oxygen to access the
waste and liquid so aerobic decay can take place. Pathogen reduction is achieved by retention time in the system, not heat. Breakdown and pathogen reduction is enhanced by local decomposers and red wiggler worms.
Site preferences—A dry, level site is preferable. If some soil
depth (4-6” or more) can be found, locate the unit there
to help absorb liquids. Trees are helpful to shade the unit
and keep the pile moist and the worms happy.
Environmental limitations—Environmental factors that
challenge use: ledges, swampy or wet ground, high water
table, nearby water sources (nearer than 200 feet); extreme
cold (where the average mean temperature never gets
above 40 degrees Fahrenheit; clay soils that do not drain
at all.
Level of use tolerated—These units are designed to be used
at low- to medium-use sites. They could be used at a higheruse site if enough cribs were constructed (NOTE—see Section 6, “Aesthetics”). GMC defines a low- to medium-use
site as one receiving no more than 500 overnight visitors
during the typical hiking season of 20 weeks.
Breakdown process—Slow aerobic (“moldering” or “mesophilic”). Uses lots of oxygen to speed the breakdown process. Also, red worms aid in breakdown by “turning” the
pile through “wriggling” and eating.
Installation issues—Crib work must be constructed properly for efficient and safe function.
Installation costs—$200 to $600 plus the outhouse.
Installation labor—More than installing a traditional pit
privy, but less than other composting toilets.
Operation issues—Red worms should be added every spring.
Maintainers should visit the unit periodically to make sure
enough wood shavings are being added and to knock over
the waste cone and mix the pile.
Operation costs—Red worms must be added periodically.
A two-pound container of worms is about $20. Worms
can be cultivated, once purchased, to reduce ongoing annual costs.
Operation labor—Minimal. Periodically packing in compressed wood shavings and adding them to the crib. Also
adding worms each spring.
Batch-bin composting—Described in Section 9 of this
manual.
Principle at work—Sewage is caught in a collector
(catcher). It is then mixed with hardwood bark chips by
hand and put into a bin where it is composted, reducing
pathogens and reducing volume. Pathogens are primarily
killed by exposure to high temperatures (100 degrees Fahrenheit and up). Remaining byproduct is placed on a platform (drying rack or screen) to cure and then is eventually scattered and some bark chips re-used.
124—APPALACHIAN TRAIL CONFERENCE —BACKCOUNTRY SANITATION MANUAL
Site preferences—Can be adapted to a variety of site conditions.
Environmental limitations—Very adaptable system. Environmental factors that challenge use: extreme slope combined with ledge; extreme cold (where the average mean
temperature never gets above 40 degrees Fahrenheit.
Level of use tolerated—High: in excess of 1,000 overnight
visitors during the typical hiking season of twenty weeks.To
accommodate higher use, a second compost bin and drying rack/screen can be added; a beyond-the-bin system
can be added to reduce amount of bark mulch needed and
thus volume.
Breakdown process—Rapid aerobic (“thermophilic”). Uses
hardwood bark chips as a bulking agent to increase airflow around waste and uses manual turning on a periodic
basis to ensure thorough breakdown.
Regulatory issues—Should not require NEPA documentation, but check with the appropriate land manager and
ATC regional office before installing.
Sanitation issues—Tests indicate that a “run” that is done
properly leaves few pathogens. Health hazard to the operator is a potential risk. Low tolerance for error in operation.
Aesthetic issues—The batch bin system has many components (bark chips, run bins, drying rack/screen, mixing
bin, etc.) that must be stored on site, making it quite bulky,
and possibly intrusive in a primitive area.
Installation issues—Must purchase a “catcher,” one or more
compost bins, and a sifting screen. Depending on the system used, two storage cans must also be purchased and a
drying rack/screen built. Those are bulky items that are
difficult to transport without vehicle or helicopter access.
Operation labor—Labor-intensive. Requires operator to
mix and turn waste by hand. High-use sites may need to
be composted biweekly, which takes several hours. Ongoing transport of bark chips to site as a bulking agent, which
may require intensive backpacking or an airlift.
Beyond-the-bin composting—Described in Section 10 of
this manual.
Principle at work—Same concept as the batch-bin
composting, but uses a special system to drain the liquids
off and then treat them. That reduces the amount of bark
required and the risk to the operator from “splash back.”
Pathogens are primarily killed by exposure to high temperatures (100 degrees Fahrenheit and up).
Site preferences—Can be adapted to a variety of site conditions. A slope is preferable to get gravity flow of liquid
to the filtering barrel.
Environmental limitations—Very adaptable system. Environmental factors that challenge use: extreme slopes combined with ledges; extreme cold (where the average mean
temperature never gets above 40 degrees Fahrenheit; clay
soils that do not drain at all.
Level of use tolerated—High: in excess of 1,000 overnight
visitors during the typical hiking season of twenty weeks.
Breakdown process—Rapid aerobic (“thermophilic”). Same
as batch-bin, but removal of liquid makes the composting
runs work more efficiently, getting hotter temperatures and
requiring less outside bark mulch.
Regulatory issues—Should not require NEPA documentation. May require a state wastewater permit.Check with
appropriate land manager and ATC regional office before
installing.
Installation costs—$1000 to $3,000 plus the outhouse.
Installation labor—Fairly labor-intensive installation to
build a new outhouse base, pack in the catcher and bin,
build a bark-chip storage unit, and build a drying rack/
screen.
Operation issues—Operator must pay careful attention to
the system and must actively compost on a frequent basis
to keep the system operational. Operator must ensure a
supply of bark chips is transported to the site.
Operation costs—A good source of hardwood bark chips is
needed. They can usually be had for free, but not always
so there may be an annual cost for mulch. Labor is an
ongoing cost, as the process is labor-intensive.
Sanitation issues—Tests indicate that the liquid that is separated out is treated sufficiently to be released into the
ground. Hazards for the operator are still present. Appropriate precautions are advised. Low tolerance for error in
operation.
Aesthetic issues—Same as batch-bin system, plus an additional pipe and leaching area that must be installed.
Installation issues—Complex installation that requires some
basic plumbing experience. Otherwise, same as batch-bin.
Installation costs—$1,100 (assumes a batch-bin system and
existing outhouse).
12: THE DECISION MAKING PROCESS—125
Installation labor—Same as the batch-bin system, but with
the addition of a more complex liquid separator in the
collector and associated drain pipes and filter barrel to
treat the liquids.
Operation issues—Same as batch-bin system. Beyond-thebin reduces the bark consumption by a third. The beyondthe-bin piping must be disconnected in the winter months
where freezing is an issue.
Operation costs—Same as batch bin, but reduces per-person bark required by a third. Labor intensive.
Operation labor—Same as batch-bin system, except that
the liquid-management system must be hooked up in the
spring and then drained and disconnected in the fall. Replacement of filter components is labor-intensive, but fortunately is infrequent.
Bio-Sun—Commercially designed continuouscomposting system, described in Section 11.4 of this
manual. For more information, contact the manufacturer.
Principle at work—A commercial system sold by Bio-Sun
Systems, of Millertown, Pa. Waste is collected in a large,
ventilated, waterproof tank. Waste material is mixed and
segregated by the operator. A beyond-the-bin liquid management system may need to be added to deal with liquid
build-up. There needs to be some way to drain and treat
liquids. Wood shavings, biological enzymes, and bark chips
are added that accelerate breakdown. Pathogen reduction
is achieved through retention time in the system, not heat.
Site preferences—The system is designed to take advantage of solar gain to power a vent fan, so the site should be
south-facing; some trees may need to be cut. May require
substantial excavation in the area of installation.
Environmental limitations—Environmental factors that
challenge use: sites that face north or west and get little
direct sunlight (system requires use of solar photovoltaic
panel for power); steep slopes; extreme cold (where the
average mean temperature never gets above 40 degrees
Fahrenheit; clay soils that do not drain at all. The system
needs some soil to drain treated effluent into. Could be
difficult to site on steep slopes with major ledge; major
excavation or blasting could be necessary.
Level of use tolerated—The manufacturer says it will accommodate 90,000 uses per year (under “optimal conditions”). Figure that the number will be slightly lower when
the unit is placed at higher elevations where the
composting season is shorter. Use levels can be better
managed with the addition of a liquid management system. Contact Bio-Sun Systems Inc. for more information.
Breakdown process—Slow serobic (“moldering” or “mesophilic”). The incline in the collection chamber allows the
waste to be “self-turning.” The addition of bark, wood
shavings, redworms, and enzymes all stimulate the breakdown process.
Regulatory issues—Will require NEPA compliance. Check
with appropriate land manager and ATC regional office
before installing.
Sanitation issues—A proven technology in a new system
format with minimal sanitation issues. Unit must be emptied on a periodic basis with proper disposal of processed
wastes. Unit is challenged at higher elevations with high
ambient air moisture. To solve the problem, a beyondthe-bin liquid-management system can be installed. Since
the tank does not gravity-separate the material, that must
be done by the maintainer. Great care must be taken that
new sewage and aged material do not get mixed. To ensure maximum pathogen reduction, finished material
should sit on a drying rack or screen for up to a year. Health
hazard to the maintainer is a potential risk due to lack of
physical segregation between fresh waste and composted
waste. There is some tolerance for error in operation.
Aesthetic issues—The Bio-Sun requires a large structure to
house the unit and may be out of place in some primitive
areas.
Installation issues—Complex installation that will require
an airlift to a remote site. A substantial building is required to house unit. A beyond-the-bin filter barrel is also
necessary to deal with liquids.
Installation costs—$10,000 to $20,000, but costs are highly
variable. Contact Bio-Sun for the exact costs of your proposed system.
Installation labor—Extensive. Installing a Bio-Sun requires
building a major structure, digging a substantial leaching
field, perhaps adding a beyond-the-bin liquid-management
system, and putting together the parts of the system that
form the chamber.
Operation issues—An on-site presence is desirable, if not
mandatory. Weekly maintenance is called for to add bark
chips /shavings and enzymes, and to rake the pile.
Operation costs—Periodically add bulking agents (usually
free) red worms (initial cost) and enzymes (ongoing minor annual expense). Labor is required to rake pile periodically.
126—APPALACHIAN TRAIL CONFERENCE —BACKCOUNTRY SANITATION MANUAL
Operation labor—Minimal, but regularity is the key. About
1
⁄2 hour per week is ideal. Most often this will include someone hiking into the site and “knocking down the cone.”
Additional periodic duty includes adding additional bulking agent.
Pennsylvania Composter—Also known as “Clivus
Minimus”; owner-built continuous-composting system. For
more information, see Appendix for plans and club contact.
Principle at work—A system styled after the Clivus
Multrum. Waste is collected in a large, ventilated, waterproof, sloping tank that has an incline that stimulates selfturning as the waste decomposes. Wood shavings, biological enzymes and bark chips are added that accelerate breakdown. A beyond-the-bin liquid-management system could
need to be added to deal with liquid build-up. There needs
to be some way to drain and treat liquids. Pathogen reduction is achieved through retention time in the system,
not heat.
Site preferences—Designed to take advantage of solar gain
to assist in temperature management. The sloping tank
and vent stack are painted black. The unit is situated with
a southern exposure and the overstory is thinned to increase solar gain. Therefore, the site should be south-facing and some trees may need to be cut. May require excavating an area for installation.
Environmental limitations—Environmental factors that
challenge use: ledges, lack of sunlight, lack of some wind,
extreme cold (where the average mean temperature never
gets above 40 degrees Fahrenheit; clay soils that do not
drain at all. Needs some soil to drain treated effluent into.
Could be difficult to site on steep slopes with major ledge;
major excavation or blasting could be necessary.
Level of use tolerated—Medium to high use, 500 or more
overnight visitors a season. Contact the Mountain Club
of Maryland for more specific information from their use
of the systems in the field.
Breakdown process—Slow aerobic (“moldering” or “mesophilic”). The incline in the collection chamber allows the
waste to be “self-turning.” The addition of bark, wood
shavings, redworms, and enzymes all stimulate the breakdown process.
Regulatory issues—Will require NEPA compliance and
compliance with state regs. Design will need to be approved. Check with appropriate local land manager and
ATC regional office.
Sanitation issues—Systems have been operating on the A.T.
in the mid-Atlantic region for several seasons with reasonable success. They were originally designed to meet
the sanitation needs along the A.T. in Pennsylvania where
the state had enacted new extremely tough waste-management standards (they banned pit toilets on the A.T.).
Currently, systems do not have a liquid management system and that affects the ability of the material to thoroughly compost.
Those systems would benefit greatly from the addition of
such a liquid drainage/management system (provided state
authorities would accept it). Additional improvements include adding enzymes and redworms. To ensure maximum
pathogen reduction, finished material should sit on a drying rack or screen for up to a year. Health hazard to the
maintainer is a potential risk. There is some tolerance for
error in operation.
Aesthetic issues—The Pennsylvania Composter (“Clivus
Minimus”) requires a large structure to house the unit and
may be out of place in some primitive areas.
Installation issues—Semi -complex installation that could
require an airlift to a remote site. For less-remote sites,
four-wheel drive or horse access is desirable. A substantial building is required to house unit. A beyond-the-bin
filter barrel could be useful, if not mandatory, to deal with
liquids. In Pennsylvania, the stringent regs regarding
ground discharge will allow leachate from the system to
drain into a drywell or “french-drain.”
Installation costs—$1,900-$2,500. Cost will vary depending on whether or not a double-chambered system is constructed.
Installation labor—Fairly labor-intensive. Installing a Clivus Minimus requires building a major structure, digging
a substantial foundation for the unit, and putting together
the parts of the system that form the chamber. The system may require a beyond-the-bin system as well as a drying screen to be constructed.
Operation issues—An on-site presence is desirable, if not
mandatory. Weekly maintenance is called for by adding
bark chips /shavings and enzymes and raking the pile.
Operation costs—Periodically add bulking agents (usually
free) redworms (initial cost) and enzymes (ongoing minor annual expense). Labor is required to rake pile periodically.
Operation labor—Minimal, but regularity is the key. About
1
⁄2 hour per week is ideal. Most often this will include someone hiking into the site and “knocking down the cone.”
Additional periodic duty includes adding additional bulking agent.
12: THE DECISION MAKING PROCESS—127
Clivus Multrum—Commercially designed continuouscomposting system. For more information, see Sections
11.3 and 11.5 of this manual, orcontact Clivus New England.
Principle at work—A commercial system sold by the Clivus New England Co. of North Andover, Massachusetts.
Waste is collected in a large, ventilated, waterproof, sloping tank that has an incline that stimulates self-turning as
the waste decomposes. Wood shavings, biological enzymes, and bark chips are added that accelerate breakdown. A beyond-the-bin liquid-management system could
need to be added to deal with liquid build-up. There needs
to be some way to drain and treat liquids. Pathogen reduction is achieved through retention time in the system,
not heat.
Site preferences—May require excavating a substantial area
for installation. May require exposure to sunlight for power
needs.
Environmental limitations—Environmental factors that
challenge use: Extreme cold (where the average mean temperature never gets above 40 degrees Fahrenheit; clay soils
that do not drain at all. Could be difficult to site on very
steep slopes or slopes combined with ledge; major excavation or blasting could be necessary to prepare such a site.
Some systems need a power supply; in a backcountry setting, photovoltaic (solar cells) may be needed to produce
power, therefore having exposure to sun is critical. System needs some soil to drain treated effluent into, or a
collection system and then means to transport collected
leachate away for safe disposal.
Level of use tolerated—Medium to high use, 500 or more
overnight visitors a season. Contact Clivus New England
for more specific information.
Breakdown process—Slow aerobic (“moldering” or “mesophilic”). The incline in the collection chamber allows the
waste to be “self-turning.” The addition of bark, wood
shavings, redworms, and enzymes all stimulate the breakdown process.
Regulatory issues—Will require NEPA compliance. Check
with appropriate land manager ATC regional office before installing.
Sanitation issues—A proven technology with minimal sanitation issues. Unit must be emptied on a periodic basis
with proper disposal of processed wastes. High-use sites in
the White Mountains have been running these systems
with great success. Carter Notch Hut went for five seasons before material had to be removed! To ensure maximum pathogen reduction, finished material should sit on
a drying rack or screen for up to a year. Health hazard to
the maintainer is a potential risk when interacting with
waste. There is some tolerance for error in operation.
Aesthetic issues—The Clivus requires a large structure to
house the unit and may be out of place in some primitive
areas.
Installation issues—Complex installation that will require
an airlift to a remote site. A substantial building is required to house unit. A Beyond-the-Bin filter barrel may
also necessary to deal with liquids.
Installation costs—Several thousand to upwards of $20,000
but costs are highly variable. check with Clivus for the
cost of your specific needs
Installation labor—Extensive. Installing a Clivus requires
building a major structure, digging a leach field (a substantial one at high-use sites), perhaps adding a beyondthe-bin liquid-management system, and putting together
the parts of the system that form the chamber.
Operation issues—An on-site presence is desirable, if not
mandatory. Weekly maintenance is called for by adding
bark chips /shavings and enzymes and raking the pile.
Operation costs—Periodically add bulking agents (usually
free) redworms (initial cost) and enzymes (ongoing minor annual expense). Labor is required to rake pile periodically.
Operation labor—Minimal, but regularity is the key. About
1
⁄2 hour per week is ideal. Most often that will include
someone hiking into the site and “knocking down the
cone.” Additional periodic duty includes adding additional
bulking agent.
13
Gray Water Management in the
Backcountry
Pete Ketcham, Field Supervisor, Green Mountain Club
Chris Thayer, Huts Manager, Appalachian Mountain Club
13.1
WHAT GRAY WATER IS
AND WHY IT NEEDS
MANAGEMENT
See Section 4, “Health and Safety
Issues.”
Gray water is waste water that has not come into contact with feces or urine. It
includes food waste, soaps and detergents, and hygienic wastes (see descriptions
below). Typically gray water is free of pathogens. But, there are exceptions, which is
why it needs management.
• Campers and hikers should always wash their hands after bowel movements. Therefore, gray water may contain pathogens, so it is a potential hazard to campsite managers and users, and it may contaminate surface and ground water. When you may
come into contact with gray water, take the same safety precautions you would
when managing raw sewage.
• Gray water can ruin backcountry water sources aesthetically. There is nothing
less appealing than dipping a cup into a spring with gobs of floating oatmeal, or a
campsite spattered with toothpaste and spit.
• Gray water also can biologically alter backcountry ponds and streams. Nutrients
can contribute to plant and algal blooms that rob aquatic animals of oxygen
when excess plants and animals die and decompose. Michael J. Caduto, in Pond
and Brook, defines this process, called eutrophication, as “the overfertilization of
aquatic ecosystems resulting in high levels of production and decomposition.
Eutrophication can hasten the aging process of a pond or lake due to the rapid
buildup of organic remains.”
Usually hikers and campers create so little gray water that this threat is minimal.
However, their gray water could add to other human-caused sources of nutrients
(old outhouse pits, for example) and natural sources to hasten eutrophication.
13: GRAY WATER MANAGEMENT IN THE BACKCOUNTRY—129
A properly sited designated washing area, washpit, or gray water management system, coupled with the education about low-impact washing practices described in
the Leave No Trace ethic, can alert backcountry users to the growing scarcity of
pure drinking water, the threat of eutrophication, and the need to keep finite potable backcountry water sources as clean as possible.
13.2
Dish washing—Dish washing in water sources water is a widespread undesirable practice that disperses food residues and nutrients from soap or detergents. Designated
washing areas and gray water management systems have helped teach hikers not to
wash dishes in drinking water sources. However, inappropriately sited, poorly constructed, or improperly maintained sites and systems can themselves create point
sources of surface and ground water pollution at medium- to high-use overnight
sites.
SOURCES OF GRAY WATER
IN THE BACKCOUNTRY
Hand washing—Hygienic waste water comes from hand washing after bowel movements, and must be considered at all backcountry sites with toilets. Sanitation systems should separate toilet users from water, especially drinking water collection
points, as much as possible. Sites with the toilet and shelter on opposite sides of
watercourses tempt users to wash their hands in streams after using the toilet.
Toiletry—Bathing, shaving, and toothbrushing can contaminate water, especially
when soaps, shaving creams, and toothpastes are used.
13.3
Fire ring—A designated fire pit can be used to dispose of limited amounts of gray
water where fires are legal. A washpit is better, but campers at a site without a
washpit may be encouraged to use the fire pit.
MANAGEMENT OPTIONS
FOR GRAY WATER
Charcoal helps absorb odors and filter effluent, and the next fire will burn food
particles too small to be packed out. However, this technique should be discouraged
where bears and other animals have been habituated to human food. The fire will
not eliminate all odors, and remaining odors will attract problem animals. Signage
should always remind campers to pack out all food scraps. The sign might suggest
that food scraps can be essentially eliminated by cooking a little less than you want
to eat, scraping pots and dishes clean, and then filling up on snacks.
Designated washing area and washpit—All washing should take place well away
from surface water. At a lightly or moderately used site, wash water should be scattered over a broad designated washing area for maximum biological assimilation.
However, at high-use sites washpits should be provided to discourage users from
washing in or near water supplies.
13.4
Siting and establishing a designated washing area—Most overnight sites need only
designated washing areas to keep them attractive and clean.
1. Site a designated washing area on the opposite side of the campsite or shelter
from the site’s water source, so the washing area will be convenient, but as far as
possible from drinking water.
DESIGNATED WASHING
AREAS
130—APPALACHIAN TRAIL CONFERENCE —BACKCOUNTRY SANITATION MANUAL
2. Pick a well-drained spot with plenty of soil. Look for vigorous undergrowth, which
indicates biologically active soil, so gray water will be utilized by plants as much
as possible. Avoid gullies with slopes to surface water. If necessary, divert surface
water away from the washpit by ditches or waterbars.
3. Try to choose an area that is unlikely to expand and increase its adverse impact
on the site. When possible, pick a spot that is already degraded. For example, try
turning an illegal tenting area into the dishwashing area, if it meets the other
criteria of a good spot.
4. Make the area easy to find. Mark it with signs, build a trail to it, and post an area
map delineating the washing area.
5. Post an obvious sign asking campers to pack out all food waste and to minimize
their use of soaps or detergents, because they pollute the backcountry.
Washpit construction and maintenance—Consider the following guidelines when
building and maintaining a designated washpit:
1. Site a new washpit on the opposite side of the campsite or shelter from the drinking water source. This increases the likelihood that dishes, etc., will stay away
from the water source. If possible, make sure the washpit is visible from the shelter.
2. Pick a well-drained spot with plenty of soil. Avoid gullies with slopes to surface
water. If necessary, divert surface water away from the pit with ditches or waterbars.
See Appendix K for a diagram of a
properly constructed washpit.
3. Dig a hole at least six inches deep—up to eighteen inches deep if soil depth
permits—but not to bedrock or hardpan. An impervious bottom will not properly filter wash water.
4. If the soil is shallow (less than twelve inches deep), dig a runway leading from
the primary pit to a second pit.
5. Fill all pits and runways loosely with flat rocks standing on edge. Use larger rocks
near the bottom, smaller rocks toward the top. Leave plenty of spaces between
the rocks so the pit will not silt up quickly. Cover secondary pits and runways
with large flat rocks to prevent them from filling with dirt, leaves and other
debris.
6. Ring the washpit with large flat rocks for users to set pots on, and to stand on,
because soil compaction around the pit quickly leads to the formation of puddles.
7. Mount an obvious “DO ALL WASHING HERE” sign on a post adjacent to the
pit. Hang an instruction sign on the post.
8. Place a fine mesh hardware-cloth screen in a frame made of pressure-treated lumber covering the washpit to exclude food scraps. Even better, provide a durable
metal colander with instructions to campers use it to strain washwater.
9. Re-dig and re-rock all pits and runways at least once a year, depending on use
levels. Silt, food particles, and grease will eventually clog the pit, although the
evil day can be put off by regularly dumping a generous amount of boiling water
into the pit.
13: GRAY WATER MANAGEMENT IN THE BACKCOUNTRY—131
Because washpits tend to be anaerobic when clogged, odors are very strong when a
pit is dug up. Wash the rocks in a five-gallon bucket and replace them. Then pour
the water in the bucket into the pit for disposal, following with hot water if possible.
10. Information on the instructional sign should remind hikers:
• Except for washing dishes and for handwashing after bowel movements, soap
and detergents are not necessary in the backcountry. The use of shaving cream
should be minimized.
• Wash nothing in streams, ponds or lakes.
• Pack out all food scraps. Food scraps can be essentially eliminated by cooking a
little less than you need and scraping the pot and dishes clean; then fill up on
snacks.
• Do not dispose of grease in the pit.
• Use as little soap and water as possible to avoid overtaxing the pit.
13.5
A gray water chute is simply a riser that caps a washpit. Chutes are especially useful
at sites that receive significant snow and winter use, because campers can find the
riser as long as it is taller than the snowpack. Deep snow usually protects the ground
and washpit from freezing, so the washpit will work through the winter.
GRAY WATER CHUTES
Chutes also help identify washpit sites, and promote their use. On the other hand,
chutes can be obtrusive, so artful placement behind at least some natural screening
is desirable.
A chute should be made of durable rust-resistant metal, or wood covered with metal
to keep animals from chewing it or vandals from burning it. The top of the chute
should expand like a funnel and have screen cover. This generous surface area provides placement for a dishpan or camping stove, so dishes can be washed in hot
water to minimize the use of soap or detergent. For gray water chute plans, contact
the AMC Huts Department .
See contact information in Appendix D.
Regular maintenance is vital—Remember that washpits and gray water chutes require inspection and maintenance annually, if not more frequently. Consider carefully whether gray water systems actually are necessary, and whether your club can
monitor and maintain them properly. Designated washing areas are adequate for
most sites.
13.6
Some states may require consultation or permits in the process of establishing a gray
water management area or system. Check with your ATC regional office before
establishing an area or system. See the Appendix for contact information for regional offices and regulatory agencies.
REGULATORY ISSUES
132—APPALACHIAN TRAIL CONFERENCE —BACKCOUNTRY SANITATION MANUAL
13.7
CASE STUDY:
GRAY WATER
MANAGEMENT AT
APPALACHIAN MOUNTAIN
CLUB HUTS
By Chris Thayer, Appalachian Mountain Club Huts Manager
Appalachian Mountain Club (AMC) huts in the White Mountains of New Hampshire use several methods for dealing with gray water waste generated by kitchen
and bathroom sinks. In some cases, gray water is combined with toilet effluent for
treatment.
Huts where sewage is airlifted out by helicopter, and those with composting toilets,
have running water in the kitchen and in the toilet rooms for washing and drinking.
These huts have grease traps and septic systems for kitchen and lavatory sink water.
After gray water leaves a grease trap, it typically goes through a pre-filter, an automatic doser, and an open valve to a filter tank and leach field.
The same basic system is used in huts with flush toilets, except that gray water
enters the sewer line after the strainer units that separate feces from waste water.
Then sewage enters the septic tank for further treatment. Every hut but one has a
grease trap with a capacity of 1,000 gallons. Lakes of the Clouds Hut, with a capacity of more than 90 guests, has a 1,500-gallon grease trap.
Caretakers clean grease traps daily by skimming and removing the contents. They
check pre-filters to guard against overflowing, and check dosers to ensure the flappers swing freely. Leach fields are rotated daily by opening or closing valves beyond
the automatic doser. Each hut has from one to four sets of filter tanks and leach
fields; only one field or tank is used at a time. Conforming with state requirements,
the AMC is eliminating chlorine based dosing systems, and is changing to simple
doser systems.
Zealand Falls Hut and Carter Notch Hut have gray water chutes, which are essentially dry wells (a washpit with a waist-high metal chute and screen—see above
description), for disposing of dish water in winter. They are left idle through the
spring, summer and fall, which allows them to dry and prevents odor. Caretakers are
responsible for maintaining screens so trash and food do not go down the chutes,
and for seeing that grease is excluded, because it will not decompose under the
anaerobic conditions typical of the pits.
Though the AMC has used a variety of methods of disposing of gray water, the club
strives for subsurface disposal through perforated pipes conforming to state codes,
because of the ease of maintenance and monitoring.
For further information on the gray water systems used by the AMC, contact Huts
Manager Chris Thayer (see Appendix for contact information).
Appendices
A—Glossary of Terms
B—Troubleshooting and General Composting Tips
C—About the Organizations behind this Manual
D—Contact List
E—Bibliography
F—Examples of Stewardship Signs
G—Sources of Materials for a Batch-Bin System
H—Lightweight Outhouse Plans
I—Plans for a Double-Chambered Moldering Privy
J—Plans for a Drying Rack
K—Diagram of a Washpit
L—Backcountry Sanitation: A Review of Literature
and Related Information
M—The Application of a Solar Hot Box to Pasteurize Toilet Compost
in Yosemite National Park
N—Examples of Regulatory Correspondence
O—Article from ATC Newsletter, The Register
P—Owner-Built Continuous Composters
Q—Plans for a Wooden Packboard
A
Glossary of Terms
Compiled by Dick Andrews, Volunteer, Green Mountain Club
ACTINOMYCETES—Single-celled, mostly aerobic organisms, closely related to bacteria, but structurally similar to fungi. They function mainly in the breakdown of
cellulose and other organic residues resistant to bacterial attack. Several, such as
Streptomyces, produce antibiotics.
AEROBIC—Requiring the presence of air or free oxygen for life.
ANAEROBIC—Living in the absence of air or free oxygen.
BACTERIA—A numerous class of both aerobic and anaerobic microscopic organisms.
They may be harmful or beneficial: Some cause disease in humans and animals;
others fix nitrogen from the air and decompose toxic wastes. Aerobic bacteria are
active in composting.
BATCH-BIN—The technique of composting organic material in large, covered waterproof containers at elevated temperatures, one batch at a time.
BEYOND-THE-BIN—A refinement of batch-bin composting in which liquid is separated from solids and treated separately.
BIOLOGICALLY ACTIVE SOIL LAYER—Soil near the surface of the ground in which organic material is abundant and many organisms live, including but not limited to
bacteria, fungi, worms and insects. This soil layer typically is moist, but loose enough
to contain many small air-filled voids.
BULKING AGENT—A material added to dense, wet and/or nitrogen-filled organic materials to facilitate composting. Bulking agents typically are high in carbon, are capable of absorbing liquid, and are finely divided to provide a lot of surface area.
They have enough strength to resist compaction and provide numerous small air
pockets, but do not tangle or otherwise impede mixing. In some cases it is useful if
the bulking agent contains splinters or other strong, sharp pieces to help chop wet
APPENDIX A: GLOSSARY OF TERMS—135
wastes during mixing. Examples of bulking agents useful in composting human waste
include bark mulch, shavings, forest duff, and chopped straw.
CHUM TOILET—A toilet without a shelter to provide privacy or protection from
weather. Chum toilets typically have been installed at pit privies, but they can also
be installed on moldering privies, vault privies and any other type of toilet that
needs no protection from the weather.
COMPOSTING—The decay or decomposition of organic material by the action of fungi,
micro-organisms and invertebrates in the presence of air. Bulk is substantially reduced, and the end product is a humus-like material with an earthy odor.
CONTINUOUS COMPOSTING—Composting in which organic material is added a little
at a time and in which decomposition proceeds at a rate approximately equal to the
rate of addition of wastes. Since the rate of adding waste is usually slow, an elevated
temperature does not normally occur, although it could happen in a large compost
pile that is receiving new waste at a high rate.
FUNGI—Plants, both microscopic and visible, which do not have chlorophyll, and
therefore cannot synthesize their food from air, water and sunlight. Fungi live on
dead or living organic matter, and include mushrooms, mildews, molds, rusts and
smuts. They are a principal agent of decomposition during composting.
LEACHATE—Liquid which has percolated through a porous mass, dissolving some of
the solids in the mass on the way. In systems composting human waste, leachate is
formed when urine or rain water percolates through feces and/or bulking agents. It
may or may not contain pathogens, depending on the conditions under which it
formed.
MESOPHILIC—Growing best at moderate temperatures, from 10 degrees C. to 40 degrees C. (50 degrees F. to 104 degrees F.). Mesophilic organisms also will grow between 4 degrees C. and 10 degrees C. (40 degrees F. to 50 degrees F), and between
40 degrees C. and 45 degrees C. (104 degrees F. to 112 degrees F.), but at these
temperatures they grow more slowly.
MOLDERING PRIVY—A mesophilic continuous -composting toilet in which human
waste and bulking agent are deposited directly on a pile contained in a crib beneath
the toilet but above ground level, separated by screening or other barriers from insects or other disease-carrying vectors, and decomposes at ambient temperature.
Redworms (also known as manure worms) may be added to speed composting.
PARASITE—An animal or plant that lives in an organism of another species, known
as the host, from which it obtains nourishment. Except in symbiotic relationships,
parasites impair the health of the host.
PATHOGEN—Any disease-producing organism.
PATHOGEN ENCAPSULATION—A process in which pathogens form durable hard outer
coatings that protect them from damage by adverse environmental conditions.
PH—A numerical representation of the acidity or alkalinity of a solution. A pH of 7
indicates a solution neither acidic nor alkaline; lower numbers indicate acidity, and
higher numbers indicate alkalinity. Each unit up or down indicates a tenfold change
in the strength of acidity or alkalinity. Composting is inhibited if the pH is too high
or too low.
136—APPALACHIAN TRAIL CONFERENCE —BACKCOUNTRY SANITATION MANUAL
PIT PRIVY—A toilet in which feces and urine are deposited directly into a pit in the
ground.
PROTOZOA—Microscopic animals consisting of one cell or a small colony of similar
cells. Some species cause serious intestinal diseases in people.
SEPTAGE (DOMESTIC)—Sewage generated by households. Domestic septage contains
human waste and wash water, but not industrial or commercial waste.
SUBSTRATE—The base or material on which an organism lives. In composting, it is
mostly the pieces of bulking agent.
THERMOPHILIC—Growing best at elevated temperatures, from 45 degrees C. (112
degrees F.) to as high as 75 degrees C. (167 degrees F.).
VAULT TOILET—A toilet in which feces and urine are deposited into a waterproof
vault, or tank, which is periodically pumped out. The sewage is then hauled to a
central sewage plant for treatment.
WATERSHED—The area drained by a stream or river.
WATER TABLE—The upper surface of ground water. Below the water table, the soil or
rock is saturated with water; above the water table, soil may be moist, but it includes
small voids filled with air.
B
Troubleshooting and
General Composting Tips
Pete Ketcham, Field Supervisor, Green Mountain Club
B.1
Below are descriptions of the most common problems in composting systems. Potential causes are listed after each problem, followed by recommended or suggested
solutions.
Problems affecting batch-bin and beyond-the-bin composting systems are addressed
first, followed by those affecting continuous composting systems. Finally, there are a
few general composting hints.
PROBLEM: The temperature of the compost pile won’t climb into the mesophilic
or thermophilic range.
Cause 1: Too much decomposition occurred while material accumulated in storage
cans, so the final addition of sewage from the full catcher was not enough to send
temperatures into the mesophilic or thermophilic range. (That does not happen
with the AMC system, since storage cans are not part of the system.)
Solution: Do not re-contaminate the pile with more fresh sewage. Turn and mix
the center portion only, and adjust moisture by adding water if the pile is too dry,
or adding bulking agent if it is too wet. Allow composting to run again for as long
as possible, at a lower temperature if need be. If storage capacity permits, add
several extra turnings to the run. Store compost on the drying rack for additional
aging.
Cause 2: Compost left in the bin over winter has decomposed and lost enough nutrients to keep the pile from heating. (That situation is of no concern in the
AMC system, since compost is left over winter in only one bin, and it has already
been through one or more cycles of heating in the first bin.)
TROUBLESHOOTING
BATCH-BIN AND BEYONDTHE-BIN SYSTEMS
138—APPALACHIAN TRAIL CONFERENCE —BACKCOUNTRY SANITATION MANUAL
Solution: If the compost does not appear finished, proceed as for Cause 1. If the
compost does appear finished, add no fresh sewage; transfer the most composted
portions to the drying rack or screen, and continue to turn it on the rack.
Cause 3 : The pile is too dry. Water in the waste may have been absorbed by excessive bulking agent in the catcher, storage container or compost bin.
Solution: Adjust moisture in the pile, and allow the compost to run again. Use
compost from the bin in place of bark when mixing and breaking up any new
wastes. Add water if needed. Water can be sprinkled on, or the bin lid can be
removed during light rain (do not leave the bin unattended with the lid removed,
or a downpour could reverse the problem). The ideal moisture level is just below
that at which water will appear on the bottom of the bin.
Cause 4: The pile is too wet. This also tends to compact the pile, reducing oxygen
availability. The wastes may have been too wet to begin with; there may not
have been enough bulking agent; the bulking agent may have been the wrong
kind or too wet; or a lid may have been displaced by wind, curious hikers or some
other cause, letting rain or snow into the system.
Solution: Soak up excess water by adding dry bulking agents to the wettest part
(usually the lowest point in the bin). Peat moss is more absorbent than hardwood bark mulch, so it will not bulk up the pile as much as bark mulch, but it is
a poor composting substrate, and should be used only as a last resort.
If bark or peat moss are not available, add old dry compost (you can spread compost on the bin lid to dry on windy, sunny days), well crumbled dry leaves, or
sawdust. If need be, remove a drier portion of the pile to make room in the bin for
more bark or peat moss. If sawdust is used, allow several days for full absorption,
or the bin can easily become over dried. Because the carbon/nitrogen (C/N)
ratio may be pushed too high by a large volume of sawdust, fresh green plants or
a little fresh sewage should be added to the compost to increase the nitrogen
content.
Under extreme circumstances, bail the water out. Use a five-gallon plastic bucket,
dig a sump in deep dry soil well away from the site, water and trails, and pour the
contaminated water a little at a time into the sump.
Secure the bin lid if it is easily dislodged. Several large rocks may help hold it in
place. Small hooks can be used, but they can scratch the operator. The GMC
drills holes through the bin lid and the lip of the composting bin and fastens the
lid to the bin with carriage bolts to deter unwanted opening during the winter.
The AMC has a fitted 60-pound plywood lid that is tied down in winter.
Cause 5 : The pile of sewage is too small to self-insulate.
Solution: Continue storing wastes, and when an appropriate amount has been
gathered (based on the remaining room in the compost bin—you want your bin
filled almost to the brim), attempt to re-ignite the biological furnace and get the
run going again..
PROBLEM: There is a backlog of sewage in the middle of processing a compost run.
Causes: Not enough storage capacity; an unexpected surge of use; a slow composting
run.
APPENDIX B: TROUBLESHOOTING AND GENERAL COMPOSTING TIPS—139
Solution: In the GMC system: add another 32-gallon storage container to the
site. In the AMC system: add another composting bin. Begin a second run with
a batch of fresh sewage.
PROBLEM: Raw sewage has been inadvertently added to a bin full of finished compost.
Causes: Winter users, or unwitting help, dumped the catcher into the bin. The run
may have been completed in fall and left in the bin, but records were not passed
on to spring operator.
Solutions: If the sewage has been dumped on but not mixed with finished compost, remove visible raw sewage to the storage cans (in the GMC system) or to
the empty compost bin (in the AMC system). Remove to the drying rack those
portions of the compost pile which are composted but have not been in contact
with raw sewage. Create enough space in the bin to add a batch of fresh sewage
and do a run (in the GMC system), or start a run in the empty bin (in the AMC
system).
If sewage has been mixed with finished compost, and there is not enough new
sewage to constitute a batch, remove enough compost from the bin to add a
batch of fresh sewage and begin a run. Put the removed (but recontaminated)
compost in an extra storage can if possible; otherwise, put it on the drying rack,
separated from other compost stored there. Use this recontaminated compost to
top the working pile, or recycle it back into the bin in the next run.
PROBLEM: Compost wintered in the bin appears stable, but the bottom is wet.
Causes: Water may have gotten in as a result of the lid of the compost bin being
askew, or wastes may have been wet when left in the fall.
Solution: Check the previous fall’s records to determine the status of the compost. Transfer drier portions of compost to the drying rack or to storage cans to
make room for a batch of fresh sewage. Use this drier compost as insulation on
top and sides of the bin if needed to fill the bin in the next run. Recycle any
remaining compost through the bin in future runs.
PROBLEM: The bin leaks.
Causes: A hole was punched in the bottom by the turning fork; porcupines have
chewed a hole in the bin, etc. (This does not happen with the AMC’s stainless
steel bins.)
Solution: Patch the hole(s). The bin must first be emptied. Use whatever containers are readily available to hold the contents; pack more in if necessary. Clean
and dry the interior and locate the hole(s).
The best way to patch a bin is with a high quality outdoor silicone caulking
compound. Apply the compound generously to both sides of the hole. Apply
several layers, with ample curing time between applications. Smooth the inside
to prevent the turning fork from catching on the caulk and pulling it out.
If possible, cover the caulking compound with a waterproof sealing paint or with
an epoxy-resin compound which will be hard when dry. The outside can be sealed
with roofing cement.
If the hole can’t be patched, replace the bin.
140—APPALACHIAN TRAIL CONFERENCE —BACKCOUNTRY SANITATION MANUAL
PROBLEM: Water appears mysteriously in the bin.
Causes : The lid leaks, or a small leak has developed in the bottom of the bin, and
water is seeping in.
Solution: Examine the lid for leaks; repair any you find. Drain water from the
compost operation by ditching around the bin, finish the run, and patch the hole
in the bin as described above. Build a platform for the bin, and place the bin on
the platform.
B.2
TROUBLESHOOTING
CONTINUOUS
COMPOSTING SYSTEMS
PROBLEM: There is an odor of fresh waste in or around the system.
Cause 1: Insufficient bulking agent is mixed with the waste.
Solution: Dense, wet waste in the composting chamber is evidence of insufficient
bulking agent. Supply a larger scoop for users to add bulking agent with each use,
or have an attendant add bulking agent periodically, stirring the waste pile if
necessary to mix the bulking agent into the pile. Make sure the supply of bulking
agent does not run out.
Cause 2: Inadequate ventilation.
On commercially made and owner-built continuous composters with waterproof
tanks, a common cause of odor in the toilet room is improper installation of the
ventilation stack, or a broken vent stack. Air can then flow down the vent stack
and into the compost chamber and then back up the toilet chute.
Solutions: To check ventilation, hold a smoldering splinter, blown-out match or a
lit cigarette near the toilet seat and observe the flow of smoke. (Take care not to
drop any source of ignition into the compost tank or chamber.) If smoke does not go
down the toilet chute, there is not enough draft, which allows odors to rise up
the toilet chute and out the seat.
Does the toilet room have good ventilation? There must be some way for air to
enter the room, or it cannot flow down the toilet chute when the toilet seat is
opened. However, make sure that there are no windows or other openings in the
ceiling or in the walls, especially on the lee side of the outhouse, where they will
tend to suck air out of the toilet room. The only openings should be small and
near the floor, ideally on the windward side. In windy locations with changeable
wind direction, try installing lightweight hinged flaps hanging downward on the
inside of ventilation openings in the toilet room, so they will open when wind
blows inward, but close when air tries to leave the room.
Make sure the top of the vent pipe is not blocked. A rain cap may have fallen
down over the top of the pipe. Insect screening may have become clogged (sometimes with dead cluster flies!). Try to locate insect screening on the outside of
the rain cap so it will not restrict air flow, and it will be washed by rain. If odor
appears in winter, check the downwind portion of the vent cap for frost buildup
(which clogs the outlet of the vent and causes wind to drive downward into the
vent), and remove the frost if possible.
If there is a fan, is it running? Be sure it is installed to blow in the right direction,
and that the vent pipe is continuous. If your system has a fan and the fan is not
working, it may be acting as an obstruction to the flow of air.
APPENDIX B: TROUBLESHOOTING AND GENERAL COMPOSTING TIPS—141
In a unit without a fan, try raising the stack higher above the roof and adding a
cap designed to enhance draft in wind. Adding a turbine ventilator to the top of
the stack (instead of a cap) may help, although turbines tend to freeze in winter.
Is the exhaust vent as straight as it could be? Just like a chimney from a wood
stove, your best draft will come if there are minimal elbows or turns in the pipe.
Make sure the toilet seat is closed when not in use; post a sign in the outhouse to
that effect.
Make sure the outhouse door is kept closed, especially if it is on the downwind
side of the building. Post a sign asking hikers to keep the door closed, or install
an automatic door closer.
Make sure trees and seasonal vegetation are kept clear of the air intake areas and
the exhaust stack. Tall trees near the toilet building can reduce draft. It may be
possible to remove a few nearby trees. Check first with your ATC regional office
and the land manager.
If the smoke test indicates air is flowing down the toilet chute but there is still an
odor, you may need to check for leaks and improperly fastened pipes and fittings.
If found, repair them.
Be sure the inspection door and emptying hatch on the compost chamber are
closed tightly, all air vents are open and unblocked, and there is a way for air to
enter the space sheltering the compost chamber.
If problems persist, one last thing you could try is to block the supplemental air
inlets to see if that forces more air to be drawn down through the toilet chute.
PROBLEM: There is a strong odor of sewage or rotten eggs.
Causes: Strong odors of this nature indicate the system may have become anaerobic
(due to compaction or liquid build-up) or that there is an imbalance of nutrients
within the pile.
Solutions: Increase aeration to increase the level of oxygen in the pile, and facilitate the evaporation of liquids, by adding more bulking agent, and perhaps red
worms and/or compost enzymes.
Often odors can be neutralized by covering the compost pile with a healthy layer
of bulking agent. Make sure there is a sign in the outhouse instructing hikers to
add bulking agent after each use, and provide a larger scoop if they are not using
enough.
Urine mixed with feces can increase objectionable odors, especially ammonia.
Separating urine or excluding it will often reduce odor. If you choose the latter
plan, check the pile regularly and sprinkle it with water if it appears dry. A drop
or two of biodegradable hand dishwashing detergent in the water helps it penetrate the pile rather than run off the surface.
Compost toilet manufacturers sell filters, generally containing granulated activated carbon, that can scrub odors from compost exhaust, but this requires forced
ventilation with a fan.
142—APPALACHIAN TRAIL CONFERENCE —BACKCOUNTRY SANITATION MANUAL
Cold wood ash is a useful and free odor control additive readily available at many
backcountry campsites. If fires are not permitted at your site, wood ash can be
packed in—not much is needed. Be certain the ash is cold. Even a single spark can
cause a destructive fire. Add ash lightly to the pile to avoid forming an impenetrable layer of ash or contributing to organic concrete (see below).
Other options are livestock odor-control additives, oxidizing agents, absorbents,
and digestive deodorants. Contact your local agricultural extension office for
more information. However, be cautious: some of these products may be incompatible with the health of decomposer organisms. Also, the land management
agency may not permit these substances.
PROBLEM: The composter doesn’t seem to be filling up, even after a year of use.
Cause: Low use of the system. This is usually not a problem on the Trail, because
these systems are generally located at heavily used sites. At lightly used sites with
a large composting chamber, it may take several seasons before the system has
any composted material to empty. Consider this a blessing! Material is decomposing as fast as it is being added, and the composting process is working very
well.
Solution: None needed.
PROBLEM: Material isn’t completely composted.
Cause: This is a major concern. In most cases, the cause is improper management of
the composting process—insufficient warmth, air or moisture; premature removal
of material; or inadequate capacity in the system.
Solutions: Avoid overloading the system. The rating of each manufactured
composting system depends on a certain minimum temperature. Most systems
base their capacity ratings on a temperature of 65 degrees F. (18 degrees C.) or
higher, and capacity usually is drastically reduced at lower temperatures.
An overloaded system develops a saturated compost mass. There is visible standing liquid, and the material drips when it is handled. There also may be a strong
odor of rotten eggs, a sure sign that the pile has gone anaerobic. Composting
slows or stops entirely, and a soupy mixture of solid and liquid accumulates.
Reducing the urine load may solve the problem. Increased evaporation also may
help: check the exhaust stack for blockage, and be sure the fan (if present) is
working. Try adding more bulking agent, or install a urine diverting toilet and
urinal, and manage urine separately. If there is a heating element (unlikely on
the A.T., unless your system is at a trailhead), check to see if it is operating
properly.
In moldering privies or commercially produced toilets with large compost chambers, liquid drains away, so upper layers of the pile may get too dry, and the
composting process will stop. If this happens, water the pile regularly with a spray
bottle or a watering can. A drop or two of biodegradable hand dishwashing detergent in the water helps it penetrate the pile rather than run off the surface.
Some systems now include liquid leachate re-spraying systems. This practice is
not recommended, because the leachate (urine percolated through the composting
mass) contains concentrated salts, ammonia, etc. that hinder the growth of decomposer organisms. Other systems include fresh water sprinkler systems. These
are useful if they can be operated manually. Some have moisture sensors, and
APPENDIX B: TROUBLESHOOTING AND GENERAL COMPOSTING TIPS—143
automatically spray the pile when it becomes too dry. Unfortunately, this is seldom practical on the A.T.
If you must remove uncomposted material, you have several options:
• Place it in storage containers, hold it until you stabilize your composting system,
and then run the material through the system again.
• Nearly finished material can be placed on a drying rack for aging.
• Bury material at a shallow depth well away from trails, water, and camping areas,
or incinerate it.
If you must dispose of partially finished material more than once, you need to
analyze your system, and make changes or implement a system that will work
correctly.
PROBLEM: Organic concrete forms in the unit.
Causes: A common cause is compaction of the compost pile due to infrequent removal of finished material.
The mixture of the salts, urine, excrement, toilet paper, and bulking agent may
be both too dense and too dry. This is can be aggravated by too much heat in
commercial systems with heating elements, a contributing factor unlikely in the
backcountry.
Some bacteria and fungi naturally produce a material called glomulin, which acts
like a glue to hold together particles. On the forest floor or in gardens, this is a
naturally occurring process that is important in producing soil structure.
Concrete-forming bacteria working in the presence of certain minerals in excrement and some bulking agents can create additional organic concrete materials.
An example of this is bacteria that use urea (a component of urine) as their
source of nitrogen. As they break down the urea, they create ammonia and ammonium hydroxide, which react with calcium, yielding calcium carbonate, the
principal constituent of limestone and concrete.
Solutions: Keep composting material uniformly moist and porous. Mixing is crucial.
However, in large continuous composters it is difficult to reach the lower
parts of the pile. Therefore, it is essential to remove finished material as it
accumulates in the cleanout chamber, so compost mixes as it tumbles toward
the cleanout door. Remove finished product at least once every two years if
you have a large, single chamber composter such as Clivus Multrum or
Minimus, Bio-Sun, CTS, or Phoenix.
If the material you remove doesn’t appear to be fully done, it can be placed on a
drying rack for additional aging and treatment.
Try to manage heat input so it evaporates some water, but keeps the pile moist.
However, too much heat is highly unlikely on the Appalachian Trail. Instead,
excessive liquid is more likely. In this case, consider a system to drain and treat
excess liquid, yet keep the pile moist.
144—APPALACHIAN TRAIL CONFERENCE —BACKCOUNTRY SANITATION MANUAL
Once it has formed, organic concrete is difficult to deal with. Break it up with a
turning fork or other long handled tool, remove it, and try to work it back into
the system after it has softened with exposure to fresh waste and moisture. If it
doesn’t soften, it will have to be incinerated or buried away from water, trails,
shelters, and campsites.
B.3
GENERAL COMPOSTING
TIPS
Pay attention to moisture.
Moisture is in the optimum range when a shovelful of material appears moist and
glistening, like a wrung-out sponge. It should not drip, and no visible standing liquid should be present in the pile. If you want to be more precise, you can use a
moisture meter. Follow the instructions for the meter, and check different parts of
the pile and various depths. However, excellent results are possible without a meter.
Keep the toilet and chute clean.
Clean surroundings encourage hikers to use the toilet rather than the woods. A
little biodegradable soap or detergent and warm water (don’t forget to pack in your
Thermos or camp stove for heating water) will not harm the composting process.
Actually, this mixture is beneficial, because it reduces the surface tension of water
in the pile, which helps water penetrate areas that might otherwise become too dry.
It also can help make organic molecules and nutrients more available to decomposers by enabling modest amounts of water to penetrate materials more thoroughly.
However, never introduce chemicals, disinfectants, bleach or other poisons into the
compost pile. These kill beneficial organisms as well as the pathogens you are trying
to eliminate. If you use them to clean the toilet seat and the area around it, dispose
of them elsewhere.
Ammonia and water is a good cleaning solution compatible with composting. Most
compost piles produce some ammonia on their own, and a little more does no harm.
A 3-percent solution of hydrogen peroxide, available at drug stores, is a disinfectant
reasonably compatible with composting. Apply it to a rag or sponge, and wipe down
the surfaces of the system. If a little gets down the toilet, it may be a little hard on
the first organisms it encounters, but as it becomes diluted through dispersal, it will
add beneficial oxygen to the system.
Discourage hikers from depositing food waste in the composting system.
Place signs asking folks to pack out all garbage. Food waste adds nutrients to the
compost pile, but this minor advantage is overwhelmed by the evil of attracting
wildlife to the pile. Also, it is a short step from food wastes to bottles, cans, plastic
bags and foil packages.
If food attracts rodents to a composter, they may get contaminated with fresh sewage, and then travel to the campsite or shelter. Do all you can to avoid attracting
wildlife, and block any way animals might enter contaminated portions of the
composting system.
C
About the Organizations Behind
this Manual
The Appalachian Trail Conference
The Appalachian Trail Conference (ATC) is a nonprofit educational organization
with more than 31,000 members dedicated to protecting and promoting the Appalachian National Scenic Trail (A.T.) along its 2,160 mile length from Maine to
Georgia. The Conference is also a federation of 31 Trail-maintaining clubs whose
volunteers manage and maintain the A.T. The Conference maintains a headquarters office in Harpers Ferry WV, and regional offices in Lyme NH; Boiling Springs
PA; Newport VA; and Asheville NC. ATC maintains a staff of approximately 40
employees, and through the Trail-maintaining clubs there are approximately 4600
volunteers that contributed 201,000 hours to Trail management and maintenance
in 2000.
The Appalachian National Scenic Trail is a unit of the US National Park system,
and is America’s first National Scenic Trail. A footpath running primarily along the
crest of the Appalachian Mountains, the Trail provides opportunities for outdoor
recreation in a natural, undeveloped environment to many thousands of people
each year. The Trail is managed as a scenic, natural and recreation resource for
those desiring a challenging outdoor recreation experience or for those who wish to
get away from the trappings of modern civilization.
The lands surrounding the Appalachian National Scenic Trail have been protected
through an extensive public land acquisition process led by the National Park Service. Under a unique series of cooperative agreements with the Department of Agriculture (USDA Forest Service) and Department of Interior (National Park Service), ATC has accepted management responsibility for a corridor of land surrounding the Appalachian Trail footpath. These “Delegation Agreements” assign responsibility for Trail management and protection to the Appalachian Trail Conference,
which in turns has delegated that responsibility to its member clubs. In effect, this
makes the Appalachian National Scenic Trail America’s only volunteer-managed
National Park.
146—APPALACHIAN TRAIL CONFERENCE —BACKCOUNTRY SANITATION MANUAL
Appalachian Trail Conference
Attn: Director of Trail Management Programs
P.O. Box 807
799 Washington St.Harpers Ferry WV 25425
(304) 535-6331
<www.appalachiantrail.org>
The Appalachian Mountain Club
The Appalachian Mountain Club (AMC) is the oldest conservation club in the
United States, with more than 88,000 members. Since 1876, the AMC has helped
people experience the majesty and solitude of the Northeast outdoors. The AMC
offers more than 100 workshops annually on a variety of outdoor subjects and many
guidebooks and maps. The AMC maintains visitor centers, backcountry shelters
and huts, and hiking and cross country ski trails in the White Mountains of New
Hampshire and the Berkshires of Massachusetts and Connecticut as well as visitor
centers throughout the Northeast from Maine to New Jersey. The club’s mission is
to promote the protection, enjoyment, and wise use of the mountains, rivers, and
trails of the Northeast.
Headquarters
Appalachian Mountain Club
5 Joy St.
Boston MA 02108
(617) 523-0636
<www.outdoors.org>
Pinkham Notch Visitor Center
Attn: Huts Manager and Shelters Supervisor
P.O. Box 298, Route 16
Gorham NH 03581
(603) 466-2721
The Green Mountain Club
Established in 1910 to build the Long Trail, the Green Mountain Club (GMC) is a
private, nonprofit organization with more than 9,000 members. Vermont’s historic
Long Trail, the first long-distance hiking trail in the United States, was the inspiration for the Appalachian Trail. The GMC is dedicated to maintaining, managing
and protecting Vermont’s Historic Long Trail System, which includes 70 overnight
facilities and 124 miles of the Appalachian Trail, and advocating for hiking opportunities in Vermont. Every year, more than 800 volunteers work so that future generations may enjoy the 445 mile Long Trail System.
Green Mountain Club
Attn: Director of Field Programs and Field Supervisor (Facilities)
4711 Waterbury-Stowe Rd.
Waterbury Center VT 05677
(802) 244-7037
<gmc@greenmountainclub.org>
<www.greenmountainclub.org>
APPENDIX C: ABOUT THE ORGANIZATIONS BEHIND THIS MANUAL—147
The Randolph Mountain Club
Founded in 1910, the Randolph Mountain Club (RMC) maintains a network of
100 miles of hiking trails and four shelters on the northern slopes of the Presidential
Range on the White Mountain National Forest in New Hampshire, and on the
Crescent Range in the town of Randolph NH. The club has approximately 500
members, and is managed by an active volunteer board of directors. The RMC is
funded by dues and donations from members, cost challenge trails contracts with
the US Forest Service, and other state and local grants.
RMC’s four shelters consist of two cabins near treeline on Mount Adams: Crag
Camp, with a capacity of 20, and Gray Knob, with a capacity of 15. There are also
two Adirondack-style shelters, The Perch and The Log Cabin, each with a capacity
of 10. Overnight fees, ranging between $5 and $8, are set to cover the basic operating expenses of the cabins. The RMC is dedicated to keeping fees as low as possible.
Caretakers at Gray Knob and Crag Camp manage the four shelters during the summer. During the rest of the year, one caretaker is in residence at Gray Knob. The
club also has two trail crews, which perform basic maintenance and erosion control
projects. In the summer, a field supervisor oversees the caretakers and trail crews,
and acts as a liaison to the board of directors.
Randolph Mountain Club
Attn: Camps Director
Randolph NH 03570
<campsdirector@randolphmountainclub.org>
<www.randolphmountainclub.org>
Appalachian Trail Park Office
The Appalachian Trail Park Office (ATPO) is the National Park Service (NPS)
office charged with carrying out the Secretary of the Interior’s responsibilities for
oversight and administration of the Appalachian National Scenic Trail under the
National Trails System Act.
Equivalent to the Park Superintendent’s office in a traditional national park, ATPO
is directed by a Park Manager. Under the unique cooperative management system
for the A.T., many traditional park-management responsibilities have been delegated
to the Appalachian Trail Conference and its member clubs. ATPO has retained
responsibility for the non-delegated functions, and has broad authority for coordinating protection and management efforts along the entire length of the A.T. ATPO
works closely and cooperatively with ATC, the 31 A.T. Clubs, other NPS units, the
USDA Forest Service, other federal agencies, and state agencies within the 14 Trail
states.
Appalachian Trail Park Office
Harpers Ferry Center
Harpers Ferry WV 25425
(304) 535-6737fax: (304) 535-6270
<pirvine@fs.fed.us>
148—APPALACHIAN TRAIL CONFERENCE —BACKCOUNTRY SANITATION MANUAL
The Center for Ecological Pollution Prevention
The Center for Ecological Pollution Prevention (CEPP) develops, promotes and
demonstrates better waste management technologies, with an emphasis on source
separation and utilization approaches. The CEPP graciously allowed the GMC and
ATC to utilize information and illustrations from their latest book The Composting
Toilet System Book (CEPP, 1999).
David Del Porto and Carol Steinfeld
The Center for Ecological Pollution Prevention
P.O. Box 1330
Concord, MA 01742-1330
(978) 318-7033 <ecop2@hotmail.com>
<http://www.cepp.cc/>
Jenkins Publishing
Publisher of The Humanure Handbook. The author, Joseph Jenkins, and his book
were an invaluable resource for the production of this manual.
Joseph Jenkins
c/o Jenkins Publishing
P.O. Box 607
Grove City, PA 16127
Phone/fax: (814) 786-8209
<jcjenkins@jenkinspublishing.com>
<www.jenkinspublishing.com>
D
Contact List
April 2001
D.1
Appalachian Trail Conference
Attn: Director of Trail Management Programs
P.O. Box 807
799 Washington St.
Harpers Ferry WV 25425
(304) 535-6331
<www.appalachiantrail.org>
ATC New England Regional Office
P.O. Box 312
18 On the Common, Unit 7
Lyme, NH 03768-0312
(603) 795-4935
Fax: (603) 795-4936
<atc-nero@appalachiantrail.org>
Regional Representative—J.T. Horn <jthorn@appalachiantrail.org>
Associate Reg. Representative—Matt Stevens <mstevens@appalachiantrail.org>
ATC Mid-Atlantic Regional Office
P.O. Box 625
4 East First Street
Boiling Springs, PA 17007
(717) 258-5771
Fax: (717) 258-1442
<atc-maro@appalachiantrail.org>
Regional Representative—Karen Lutz <klutz@appalachiantrail.org>
Associate Reg. Representative—John Wright <jwright@appalachiantrail.org>
Associate Reg. Representative—Michelle Miller <mmiller@appalachiantrail.org>
APPALACHIAN TRAIL
CONFERENCE AND REGIONAL OFFICES
150—APPALACHIAN TRAIL CONFERENCE —BACKCOUNTRY SANITATION MANUAL
The Mid-Atlantic Regional Office is a good source of information on how to work
effectively with strict state regulators when contemplating sanitation system upgrades on the A.T. Pennsylvania has stringent regulations for management of human waste in the backcountry.
ATC Central and Southwest Virginia Regional Office
P.O. Box 10
103 Old Newport Road, Suite A
Newport, VA 24128
(540) 544-7388
Fax: (540) 544-7120
<atc-varo@appalachiantrail.org>
Regional Representative—Teresa Martinez <tmartinez@appalachiantrail.org>
Associate Regional Representative—Jody Bickell <jbickell@appalachiantrail.org>
ATC Tennessee, North Carolina, and Georgia Regional Office
P.O. Box 2750
160 Zillicoa Street
Asheville, NC 28802
(828) 254-3708
Fax: (828) 254-3754
<atc-gntro@appalchiantrail.org>
Regional Representative—Morgan Sommerville
<msommerville@appalachiantrail.org>
Associate Regional Representative - VACANT - TBA
D.2
APPALACHIAN TRAIL
PARK OFFICE
Appalachian Trail Park Office
Harpers Ferry Center
Harpers Ferry WV 25425
(304) 535-6737
Fax: (304) 535-6270
<pirvine@fs.fed.us>
D.3
TRAIL-MAINTAINING CLUBS
New York-New Jersey Trail Conference
156 Ramapo Valley Road (Route 202)
Mahwah, NJ 07430
(201) 512-9348 M-F 11a.m.-5:30 p.m. or leave a message any time.
Fax: (201) 512-9012
<info@nynjtc.org>
<www.nynjtc.org>
New Jersey Field Office
PO Box 169
McAffee, NJ 07428
(973) 823-9999
Fax: (973) 823-9999
APPENDIX D: CONTACT LIST—151
Appalachian Mountain Club Headquarters
5 Joy St.
Boston MA 02108
(617) 523-0636
<www.outdoors.org>
AMC Pinkham Notch Visitor Center
Attn: Huts Manager and Shelters Supervisor
P.O. Box 298, Route 16
Gorham NH 03581
(603) 466-2721
The Green Mountain Club, Inc.
4711 Waterbury-Stowe Road
Waterbury Center, VT 05677
(802) 244-7037
Fax: (802) 244-5867
<gmc@greenmountainclub.org>
<www.greenmountainclub.org>
Director of Field Programs—Dave Hardy Ext. 20 <dave@greenmountainclub.org>
Field Supervisor (ATC Sanitation Manual Co-Author and Contact) —Pete Ketcham.
Ext. 17 <pete@greenmountainclub.org>
Randolph Mountain Club
Attn: Camps Director
Randolph NH 03570
<campsdirector@randolphmountainclub.org>
<www.randolphmountainclub.org>
The Mountain Club of Maryland
4606 Waterfall Court #A,
Owings Mills, MD 21117
(410) 377-6266
< http://www.mcomd.org>
Contact: Ted Sanderson
MCM manages the Pennsylvania Composting System or “The Clivus Minimus.”
Ted Sanderson designed the Pennsylvania Composter and is a good source of
information on owner-built composters.
Blue Mountain Eagle Climbing Club
P.O. Box 14982
Reading, PA 19612-4982
< info@bmecc.org>
<www.bmecc.org>
Contact: Dave Crosby
Dave has extensive experience operating batch-bin composters without paid seasonal staff.
152—APPALACHIAN TRAIL CONFERENCE —BACKCOUNTRY SANITATION MANUAL
D.4
REGULATORY CONTACTS
FOR THE APPALACHIAN
TRAIL, LISTED BY STATE
Compiled by Pete Ketcham, Field Supervisor, Green Mountain Club
Please use this contact list for general purposes only. Many parties must be consulted before a backcountry sanitation system can be installed, and regulations and
the agencies enforcing them often change. Please contact your ATC regional office
for more detail.
Sometimes local health officials have the authority to make final decisions. If they
deny permission for a backcountry sanitation system, check with state officials, especially if they are familiar with innovative sanitation systems. Many composting
toilet projects in residential areas are approved this way.
The following information comes to the ATC courtesy of David Del Porto and Carol
Steinfeld, authors of The Composting Toilet System Book. Del Porto and Steinfeld
sent out a questionnaire in 1999 to every state, and followed it with several phone
calls. Some states were not forthcoming, so the information may be incomplete.
Also, Del Porto and Steinfeld asked mainly about frontcountry and residential applications of composting toilet system technology, so make sure you ask about regulations concerning the backcountry.
It is best to consult your local club leadership, your ATC regional office staff, and
the local land manager(s) first, to learn the best way to approach regulatory officials. Then call your state department of health or environment protection agency.
For More Information on Regulations
The National Small Flows Clearinghouse (NSFC)—NSFC, sponsored by the U.S. Environmental Protection Agency, offers a free list of state contacts for onsite systems,
as well as a regulations repository. For a fee you can get your state’s onsite system
approval regulations, although you will have to determine the which requirements
are relevant on your own. Call (800) 624-8301.
According to the clearinghouse, “homeowners and developers may have a hard
time getting approval for some systems because of inflexible regulations or because health officials are unaware of certain alternative system designs or have
questions concerning their performance, operation or maintenance.” The clearinghouse offers many technical bulletins and publications about onsite and small
community systems (Del Porto & Steinfeld, The Composting Toilet System Book
pp. 202).
National Small Flows Clearinghouse
P.O. Box 6064
Morgantown, WV 26505-6064
<www.nsfc.wvu.edu>
The National Sanitation Foundation (NSF)—NSF International, Inc. is an independent, nonprofit organization that develops standards for public health technologies,
including sanitation systems. The group works closely with the American National
Standards Institute (ANSI) to develop standards of performance. NSF is internationally recognized by regulators, who will usually approve a product or system listed
or approved by the NSF.
Commercially made composting toilets are tested against ANSI/NSF 41-1998 Non
Liquid Saturated Treatment Systems. This test covers a wide range of specifications,
but most importantly it covers pathogen testing. For more details on what specifi-
APPENDIX D: CONTACT LIST—153
cations and pathogens are tested, see pg. 202 in the Composting Toilet System Book
by Del Porto and Steinfeld.
Listing by NSF almost guarantees that a state or local regulator will approve a commercially designed composter.
NSF International
3475 Plymouth Road
P.O. Box 130140
Ann Arbor, MI 48113-0140
(734) 769-8010
<info@nsf.org>
<www.nsf.org>
Local Certifying Agencies
Some states, such as Massachusetts, have developed their own testing facilities, and
offer their own state approvals. Call your regional ATC field office to see if your
town, county or regulators have pertinent regulation information on sanitation
systems.
When discussing a proposed backcountry sanitation system with regulators, always
bring as much literature on your proposal as you can, to help educate them. Often
they are unaware of technologies suitable for the backcountry, and if you give them
information and time to absorb it, they may become remarkably cooperative—possibly even helpful and grateful.
For example, the Green Mountain Club had to apply for a wastewater permit when
installing a beyond-the-bin system at Butler Lodge on Mt. Mansfield in Vermont.
When the permit administrator was given the Appalachian Mountain Club’s Manual
for the beyond-the-bin system, which was designed by a licensed septic designer, the
GMC received its permit.
State Regulatory Agencies
Georgia
Georgia Department of Human Resources
Environmental Health Section
2 Peachtree St. NW
Atlanta, GA 30303-3186
(404) 657-6534
Composting toilets (commercially manufactured) must be NSF or equal certified. Systems certified by an engineer may be approved as an experimental system. Check with the ATC Georgia, North Carolina, Tennessee Regional Office
before contacting the state with a sanitation project request.
Tennessee
Tennessee Department of Environment and Conservation
Division Of Groundwater Protection
10th Floor, L7C Tower
401 Church Street
Nashville, TN 37243-1540
(615) 532-1540
<www.state.tn.us/environment/gwp/index.html>
154—APPALACHIAN TRAIL CONFERENCE —BACKCOUNTRY SANITATION MANUAL
Composters must be listed with NSF up to standard 41. A non-traditional gray
water system could be applied for as experimental. Check with the ATC Georgia, North Carolina, Tennessee Regional Office before contacting the state with
a sanitation project request.
North Carolina
Environmental Permit Information Center
(919) 715-3271
Composters may be permitted if you can present plans and/or manufacturer’s
specifications to the permitting officials. Gray water must be disposed of subsurface (although some alternatives have been approved). Check with the ATC
Georgia, North Carolina, Tennessee Regional Office before contacting the state
with a sanitation project request.
Virginia
Virginia Office of Environmental Health Services
Main Street Station, Suite 117
P.O. Box 2448, Rm. 119
Richmond, VA 23218-1448
<www.vdh.state.va.us>
<dalexander@vdh.state.va.us>
A composting toilet that meets NSF Standard 41 can be approved for a site in
Virginia wherever a pit privy can be used. The regulations can be found on the
state’s web site listed above. Check with the ATC Virginia Regional Office before contacting the state with a sanitation project request.
West Virginia
Environmental Health Services
Public Health Sanitation Division
815 Quarrier St., Suite 418
Charleston, WV 25301
Composting toilets and gray water systems are addressed in West Virginia Interpretive Rules (BoH) which was updated by Title 64, Series IX, and apply to local
boards of health. They will require design data sheet and plans for the system you
are proposing. Check with the ATC Mid-Atlantic Regional Office before contacting the state with a sanitation project request.
Maryland
Maryland Department of Environment
Water Management Administration
2500 Broening Highway
Baltimore, MD 21224
(410) 631-3780
<www.mde.state.md.us>
NSF listing will approve a commercially designed composter. Gray water management systems are approved on a case by case basis under the Innovative and
Alternative Program (make sure you inquire about this program and see if ownerbuilt composters can get approval). Check with the ATC Mid-Atlantic Regional
Office before contacting the state with a sanitation project request.
APPENDIX D: CONTACT LIST—155
Pennsylvania
Department of Environmental Resources
Division of Certification, Licensing and Bonding
Market Street State Office Building, 1st floor
400 Market Street
Harrisburg, PA 17101-2301
(717) 787-6045
Pennsylvania is known among AT maintainer circles for the toughest regulations on the Trail. However, the Mountain Club of Maryland and the Blue Mountain Eagle Climbing Club have successfully gotten composters approved. The
main challenges are how to treat leachate and gray water. Check Msection 73.1
(V) of the Pennsylvania Code, Title 25, which addresses composting toilets. Check
with the ATC Mid-Atlantic Regional Office before contacting the state with a
sanitation project request.
New Jersey
New Jersey Department of Environmental Protection
Division of Water Quality
Bureau of Nonpoint Pollution Control
P.O. Box 29
Trenton, NJ 08625-0029
(609) 292-0407
Apply at the county level. Composting toilets are subject to Chap. 199 of the
New Jersey code for individual onsite systems. Composters require approval of
building codes and local health departments. Composters and gray water systems
must comply with the Uniform Plumbing Code. Check with the ATC Mid-Atlantic Regional Office and the New Jersey Field Representative of the New YorkNew Jersey Trail Conference before contacting the state with a sanitation project
request.
New York
New York State Department of Health
Bureau of Community Sanitation and Food Protection
2 University Place, Room 404
Albany, NY 12203-3300
(518) 458-6706
Composters must be NSF listed and have a five-year warranty (this obviously
applies to commercially designed systems). Currently New York is approving the
installation of more than 100 composters for a lakeside community so this state
may be very amenable to owner-built composting toilet systems, provided they
have a well-thought-out, tested plan and have been approved in other states.
Check with the ATC Mid-Atlantic Regional Office and the New York-New Jersey Trail Conference before contacting the state with a sanitation project request.
Connecticut
Connecticut Department of Environmental Protection
Permits & Enforcement
State Office Building
165 Capitol Ave.
Hartford, CT 26115
(860) 240-9277
156—APPALACHIAN TRAIL CONFERENCE —BACKCOUNTRY SANITATION MANUAL
Local and state health departments have been designated by the DEP to permit
onsite systems. Plans must be certified by a professional engineer. Check with
the ATC New England Regional Office before contacting the state with a sanitation project request.
Massachusetts
Executive Office of Environmental Affairs
Department of Environmental Protection
1 Winter Street
Boston, MA 02108
(617) 292-5500
<www.state.ma.us/dep/>
Composting toilets are generally approved. Gray water systems are also generally
approved if submitted to the state by a professional engineer or a registered sanitarian. Check codes 310 CMR 15.289(3) (a) of the State Environmental Code
and 240 CMR 2.02 (6)(b) Basic Principles of the Uniform State Plumbing Code.
Pete Rentz (one of this manual’s authors) and the Appalachian Mountain Club
(AMC) Berkshire Chapter Massachusetts Appalachian Trail Committee have
installed several successful hybrid moldering privies. (For a case study of this
system, see Chapter 8, Case Studies.) Contact Pete Rentz to get a copy of the
Moldering Privy Manual produced by the AMC Berkshire Chapter.
Check with the ATC New England Regional Office before contacting the state
with a sanitation project request.
Vermont
Agency of Natural Resources &
Department of Environmental Conservation
Waste Water Management Division
103 South Main St.
Sewing Building
Waterbury, VT 05671-0405
(802) 241-3027
The Green Mountain Club (GMC) has many batch-bin, beyond-the-bin, and
moldering privies in the backcountry of Vermont. In general, all that is needed is
the permission of the land managing agency. This is the US Forest Service on
the Green Mountain National Forest or the Vermont Department of Forests,
Parks and Recreation on state lands.
Check with the GMC Field Office and the ATC New England Regional Office
before contacting the state with a sanitation project request.
New Hampshire
New Hampshire Department of Environmental Services
Bureau of Wastewater Treatment
6 Hazen Drive
Concord, NH 03301
(603) 271-3711
New Hampshire approves composting toilets, and the Appalachian Mountain Club
(AMC) has many composting toilets on the A.T. Gray water systems are approved
on a case-by-case basis. AMC has several alternative gray water management systems. Check with the AMC Trails Department and the ATC New England Regional
Office before contacting the state with a sanitation project request.
APPENDIX D: CONTACT LIST—157
Maine
Wastewater and Plumbing Control Program
Division of Health Engineering
10 Statehouse Station
Augusta, ME 04333-0010
(207) 287-5695
<james.jacobsen@state.me.us>
Contact: James Jacobsen, Environmental Specialist IV
Maine is generally friendly to composting toilets. The Maine Appalachian Trail
Club (MATC) has installed AMC-styled beyond-the-bin and GMC-styled batchbin composters, and plans to install moldering privies. Commercial systems must
generally be NSF listed. Check with the ATC New England Regional Office
before contacting the state with a sanitation project request.
D.5
David Del Porto and Carol Steinfeld
The Center for Ecological Pollution Prevention
P.O. Box 1330
Concord, MA 01742-1330
(978) 318-7033
<ecop2@hotmail.com>
<http://www.cepp.cc/>
OTHER ORGANIZATIONS
Joseph Jenkins
c/o Jenkins Publishing
P.O. Box 607
Grove City, PA 16127
Phone/fax: (814) 786-8209
<jcjenkins@jenkinspublishing.com>
<www.jenkinspublishing.com>
D.6
Companies in the following list have supplied information used in this manual, but
the list is not an endorsement of them or their products. There are many other
companies in this business, and a more complete listing can be found in The
Composting Toilet System Book, by David Del Porto and Carol Steinfeld. (See the Bibliography, also in the Appendix, for information on the book.)
Clivus New England, Inc.
P.O. Box 127
North Andover, MA 01845
(978) 794-9400
Fax: (978) 794-9444
<123cne@clivusne.com>
< http://clivus.com/ClivusNE/clivusne.htm>
Contact: Bill Wall or Ben Canonica
Clivus Multrum New England, Inc. is the East Coast distributor of Clivus Multrum
Systems. Clivus New England has several composting systems. They provide
COMMERCIAL
COMPOSTING TOILET
MANUFACTURERS
158—APPALACHIAN TRAIL CONFERENCE —BACKCOUNTRY SANITATION MANUAL
consultation, turnkey systems, and in some instances, maintenance services. Even
if you are not considering a Clivus, it is worth calling and getting an information
package. To see Clivus systems in operation on the A.T., contact the Appalachian Mountain Club’s Pinkham Notch Visitor Center (see above for listing).
Bio-Sun Systems, Inc.
RR#2, Box 134A
Millerton, PA 16936
(800) 847-8840
(570) 537-2200
Fax: (570) 537-6200
<info@bio-sun.com>
<www.bio-sun.com>
Contact: Allen White
BioSun Systems, Inc. is the manufacturer and distributor of the Bio-Sun line of
composting toilets. Like Clivus, Bio-Sun offers several systems and services for
special needs, including backcountry applications. To see Bio-Sun systems in
operation in the backcountry near the A.T., contact the Randolph Mountain
Club (see above for listing).
E
Bibliography
Books
Appalachian Trail Conference. 1997. Local Management Planning Guide (Second
Edition). Appalachian Trail Conference, Harpers Ferry, WV.
Applehof, M. 1982. Worms Eat My Garbage (Revised Edition). Flower Press,
Kalamazoo, MI.
Birchard, W.J.R. and R.D. Proudman. 2000. Appalachian Trail Design, Construction
and Maintenance (Second Edition). The Appalachian Trail Conference, Harpers
Ferry, WV
Campbell, S. 1975. Let it Rot! The Home Gardeners Guide to Composting. Storey
Communications, Inc. Pownal, VT.
Del Porto, D. and C. Steinfeld. 1999. The Composting Toilet System Book: A practical
guide to choosing, planning, and maintaining composting toilet systems, an alternative
to sewer and septic systems: technologies, sources, applications, gray water issues, and
regulations. The Center For Ecological Pollution Prevention, Concord, MA.
Dindal, D.L. 1972. Ecology of Compost: A Public Involvement Project. New York State
Council of Environmental Advisors and the State University of New York College of Environmental Science and Forestry. Syracuse, NY.
Dindal, D.L. 1980. Life within the Composting Toilet—Individual Onsite Waste Management Systems. McClelland, N.I. Editor. Ann Arbor Science Publishing, Ann
Arbor, MI.
Goldstein, J. 1977. Sensible Sludge. Rodale Press, Emmaus, PA. 184 pp.
Golueke, C.G. 1977. Biological Reclamation of Solid Wastes. Rodale Press, Emmaus,
PA. 249 pp.
Grant, N. M. Moodie, and Weedon C. 1996. Sewage Solutions, Answering the Call of
Nature. Centre for Alternative Technology Publications. Wales, UK
160—APPALACHIAN TRAIL CONFERENCE —BACKCOUNTRY SANITATION MANUAL
Harper, P. 1998. Fertile Waste. Centre for Alternative Technology Publications. Wales,
UK.
Jenkins, J.C. 1999. The Humanure Handbook: A Guide to Composting Human Manure. Second Edition. Jenkins Publishing, Grove City, PA.
Leonard, R.E, E.L Spencer, and H.J. Plumley. 1981. Backcountry Facilities: Design
and Maintenance. Appalachian Mountain Club, Boston, MA. 214 pp.
Pacey, A. Sanitation in Developing Countries. John Wiley & Sons Ltd. Great Britain.
238 pp.
Poindexter, J.S. 1971. Microbiology, An Introduction to Protists. The MacMillan Company, New York. 582 pp.
Ryn, S.V. 1978. The Toilet Papers—Recycling Waste and Conserving Water. Ecological
Design Press. Sausalito, CA.
Stoner, C.H. 1977. Goodbye to the Flush Toilet. Rodale Press, Emmaus, PA. 285 pp.
Martin, J.P. and D.D. Focht. 1977. Biological Properties of Soils. pp. 115-162. In
L.F. Elliot and F.J. Stevens, co-editors. Soils for the Management of Organic Wastes
and Waste Waters, SSSA, ASA, CSSA, Madison, WI.
Journals
Cappaert, J.S., O. Verdonck, and M. De Boodt. 1975. Composting Hardwood Bark.
Compost Science 16(4): 12-15.
Dindal, D.L. 1985. Soil animals and soil fabric productions: facts and perceptions.
Quaestiones Entomologicae 21:587-594.
Dindal, D.L. 1978. Soil organisms and stabilizing wastes. Compost Science 19(4) : 811.
Goleuke, C.G. 1982. When is compost “safe?”. BioCycle 23(2) : 28-36.
Golueke, C.G. 1983. Epidemiological aspects of sludge handling and management—
Part II. BioCycle 24(4): 50-57.
Haug, R.T. 1986. Composting process design criteria, part II—detention time.
BioCycle 27(8) : 36-39
Leonard, R.E. and H.J. Plumley. 1979. Human Waste Disposal in Eastern Backcountry. Journal of Forestry 77(5): 349-352.
Leonard, R.E. and S.C. Fay. 1979. Composting privy wastes at recreation sites. Compost Science/Land Utilization 20(1) : 36-39.
McKinley, V.I. and J.R. Vestal. 1985. Effects of different temperature regimes on
microbial activity and biomass in composting municipal sewage sludge. Canadian Journal of Microbiology 31:919-925.
McKinley, V.L., J.R. Vestal, and A.E. Eralp. 1985. Microbial activity in compost.
BioCycle 26(6): 39-43.
APPENDIX E: BIBLIOGRAPHY—161
Nesbitt, P.M. 1980. Biological management at land application sites. Compost Science/Land Utilization 21(2): 47-49.
Nichols, D., D. Prettyman, and M. Gross. 1983. Movement of bacteria and nutrients from pit latrines in the boundary waters canoe area wilderness. Water, Air,
and Soil Pollution 20:171-180.
Temple, Camper, and Lucas. 1982. Potential health hazards from human waste disposal in wilderness. Journal of Soil and Water Conservation 37(6):357-359.
Government Publication
Davis, B.S. and R.E. Leonard. 1984. A Manual for Bin Composting. USDA Forest
Service, Northeastern Forest Experiment Station, Durham, NH. 68 pp.
Fay, S.C. and R.H. Walke. 1977. The Composting Option for Human Waste Disposal
in the Backcountry. USDA Forest Service Research Note NE-246. The Northeastern Forest Experiment Station & Forest Service, US Dept. of Agriculture.
Upper Darby, PA.
Forest Service, USDA. June 1990. Forest Service Manual 7400: Public Health and
Pollution Control Facilities. WO Amendment 7400-90-1.
Interior, U.S. Department of the. August, 1999. Director’s Order #83: Public Health.
National Park Service.
Land, Brenda. July 1995. Composting Toilet Systems, Planning, Design, and Maintenance. USDA Forest Service, San Dimas Technology and Development Center.
(#9523 1803-SDTDC)
Land, Brenda. May 1995. Remote Waste Management. USDA Forest Service, San
Dimas Technology and Development Center. (#9523 1202-SDTDC)
Manual
Davis, B.S. and P. Neubauer. 1995. Manual for Bin Composting and Remote Waste
Management. Green Mountain Club, Waterbury Center, VT.
Proceedings
Dindal, D.L., and L. Levitan. 1976. The soil invertebrate community of composting
toilets. Proceedings VI Colloquium of Soil Zoology. Uppsala, Sweden.
F
Examples of Stewardship Signs
Figure F.1—Composting Toilet Do’s & Don’ts” from The Composting
Toilet System Book by David Del Porto and Carol Steinfeld.
APPENDIX F: EXAMPLES OF STEWARDSHIP SIGNS—163
Figure F.2—An outhouse stewardship sign for a pit toilet. Sign from the Green Mountain Club.
164—APPALACHIAN TRAIL CONFERENCE —BACKCOUNTRY SANITATION MANUAL
Figure F.3—An outhouse stewardship sign for a moldering privy composting system. Sign from the Green Mountain Club.
APPENDIX F: EXAMPLES OF STEWARDSHIP SIGNS—165
Figure F.4—One of the Green Mountain Club moldering privy outhouse stewardship signs. Note that this sign asks users not
to urinate in the toilet. In this system, the maintainer periodically waters the pile to keep it moist. Some in the backcountry
sanitation community feel that excluding urine reduces odors and curtails pathogen travel into the soil. Sign from the Green
Mountain Club.
166—APPALACHIAN TRAIL CONFERENCE —BACKCOUNTRY SANITATION MANUAL
Figure F.5—A moldering privy outhouse stewardship sign on the A.T. in southern Vermont at Little Rock Pond Shelter. Notice
that this sign recommends folks urinate in the toilet. There is some debate in the backcountry sanitation community about the
desirability of including urine urine in moldering privies. Sign from Dick Andrews, Green Mountain Club.
APPENDIX F: EXAMPLES OF STEWARDSHIP SIGNS—167
Figure F.6—A warning sign to keep the public out of a composting system area and components. Sign from the Green
Mountain Club.
168—APPALACHIAN TRAIL CONFERENCE —BACKCOUNTRY SANITATION MANUAL
Figure F.7—The outhouse stewardship sign used at the Randolph Mountain Club’s Bio-Sun systems. Sign from the Randolph
Mountain Club.
APPENDIX F: EXAMPLES OF STEWARDSHIP SIGNS—169
Figure F.8—A sign, including a schematic drawing, designed to be placed in shelters and near washpits to explain to hikers
how and why to use the washpit. Drawing from the Green Mountain Club.
170—APPALACHIAN TRAIL CONFERENCE —BACKCOUNTRY SANITATION MANUAL
Figure F.9—A washpit stewardship sign. Sign from the Green Mountain Club.
APPENDIX F: EXAMPLES OF STEWARDSHIP SIGNS—171
Figure F.10—An outhouse stewardship sign for a batch-bin or a beyond-the-bin composting toilet system. Sign from the
Green Mountain Club.
G
Sources of Materials for GMC
Batch-bin System
CATCHERS STORAGE
CANS AND COMPOST
BIN-SIZE CONTAINERS
AND LIDS
Polyethylene, round, blue aquaculture tanks 210, 250, 400 gallons 25 year life
expectancy GMC uses 210 gallon size for new and replacement bins.
Bonar Plastics
125 N. Christopher Ct.
P.O. Box 1080
Newman, GA 30264
The Tank Depot of RI, Inc.
530 Wellington Ave.
Cranston, RI 02910
(401) 941-8151
Contact: Robin Jones, Pres.
NVF Container Division
P.O. Box 340
Hartwell, GA 30643
1-800-241-8044
Call for catalog.
Makes a wide variety of collection and round tubs, and rectangular bin size containers.
Custom Fabricated Cylindrical Compost Bin Lid (designed to fit compost bin
listed above)
The Tank Depot of RI, Inc.
530 Wellington Ave.
Cranston, RI 02910
(401) 941-8151
Contact: Robin Jones, Pres.
APPENDIX G: SOURCES OF MATERIALS FOR A BATCH-BIN SYSTEM—173
70 Gallon Stock Tank with Built-in Drain Plug.
United States Plastic Corp.
1390 Neubrecht Road
Lima, Ohio 45801
(800) 537-9724
Consolidated Plastics Company, Inc.
8181 Darrow Road
Twinsburg, Ohio 44087
(800) 362-1000
32 Gallon Square Storage Cans
Obtain or Order from your local hardware store or garden supply center
(These are typically used as trash cans.)
AMC Style Packboard Supplies
Page Belting
Concord, NH 03301
(603)225-5523
(Leather harness pieces)
$50 minimum order
Fortune, Inc190 Route 1
Falmouth, Maine 04105
(AMC packboard corset)
Composting Thermometer
Scale - 200 to 2200
Johnny’s Selected Seeds
Foss Hill Rd. Albion, Maine
04910-9731
(207)437-4301
Additional supplies of materials for Batch-Bin composting may be located in the:
Thomas Register of American Manufacturers
Thomas Publishing Company
One Penn Plaza, New York, NY 10001
(available through many libraries)
H
Lightweight Outhouse Plans
H.1
PRIVY
The hardware used on this project consists of three inch screws used on the framing
and 5d galvanized box nails for attaching the shiplap sheathing. When I mention to
toe nail something I mean to use screws not nails. This entire frame should be constructed before going out into the field, this will prevent any unforseen problems
and make it easier to construct at the site. Also the exact dimensions of the interior
sheating are not given, especially for the toilet seat, so you will need to figure these
out and cut them to size.
1. Cut the two by fours into the lengths shown on the materials list. For parts D, E
and K cut a 20 degree angle and then cut to length.
2. Begin with the base frame, this includes all of the pressure treated material used
for this structure. Assemble parts A, B and C as shown in Base view.
3. Take pans F and G and screw them together as shown in the seat construction
detail.
4. Next screw parts J2 and J3 between parts E.
5. Toe nail the previous section to the base and then attach both sections of F/G to
it. Sections F/G can then be attached to the base frame. Now the back wall is
secure.
6. Fit part H between the two sections of F/G as shown in the seat construction
detail.
7. Next screw both parts I between parts H and J3.
8. Attach part JI between parts D and toe nail this section onto the front of the base
frame.
9. Screw both parts K onto parts D and E, the angled end should be towards the
front as shown on the side view. Leave an approximately 10 inch overhang on
both the front and back.
APPENDIX H: LIGHTWEIGHT OUTHOUSE PLANS—175
10.Attach the four parts L as they are shown on the side view. There should be a 19
inch space between the interior parts. In the space will go the spacers M
At this point the framing is finished.
11.Attach parts 0 to parts D, making sure there is a 3/4 inch reveal on the interior
(see Front Trim view). This reveal will act as a stop for the door. The resulting 3/
4 inch overhang will cover the butt ends of parts Q. Parts O should also go one
inch below the joint between part D and the base frame (see the close up on
Lower Trim view). Part N will fit between parts O on top to finish off the molding, again provide a 3/4 inch reveal to act as a stop.
12.Start the first course of sheathing on the back, snug, up against parts K. There
should be 13 pieces of part P. Then start attaching the 26 pieces of Q (13 courses
per side) to the sides. These will butt up against trim part O and cover the ends of
parts P.
13.Next start fastening down the interior sheating of the seat, seat front and the
floor, this should take around 14 pieces of part P. Three pieces of part P will cover
the seat front. Also you will have to cut a hole slightly larger than the toilet seat
opening.
14.The last step is to attach the metal roofing. This consists of one piece of three by
six foot roofing and another six foot section cut in half widthwise. Make sure this
half piece has a "raised" ridge on both sides, so that the pieces overlap and you
have something to screw into. Also make sure that it overhangs half an inch over
parts K on the front and back.
15.The door will consist of six boards (T) attached with a double Z-brace (parts R,
S) along the back (see Door view). Attach this to the door frame. Install the
toilet seat. Take a four foot section of the fiberglass screening and install it between part K and the top course of part Q on both sides.
The privy is now completed.
H.2
A. 2" x 4" x 47" Pressure Treated (2)
B. 2" x 4" x 32” Pressure Treated (3)
C. 2" x 4" x 18 1/2" Pressure Treated (2)
D. 2" x 4" x 81" (2)
E. 2" x 4" x 64 1/2" (2)
F. 2" x 4" x 15" (2)
G. 2" x 4"x 20 1/2" (2)
H. 2" x 4" x 32" (1)
I. 2" x 4" x 22 1/2" (2)
J. 2" x 6" x 28" (3)
MATERIALS LIST-PRIVY
176—APPALACHIAN TRAIL CONFERENCE —BACKCOUNTRY SANITATION MANUAL
K. 2" x 4" x 71" (2)
L. 2" x 4" x 56 1/4" (4)
M.2" x 4" x 19" (6)
N. 1" x 4" x 29 1/2" (1)
0. 1" x 4" x 83 1/2" (2)
P 1" x 6" x 35" (27) Shiplap
Q. 1" x 6" x 47 3/4" (26) Shiplap
R. 1" x 6" x 27" (3)
S. 1" x 4" x 40" (2)*
T. 1" x 6" x 80" (6) Shiplap
* cut to this size first
H.3
RECOMMENDED WOOD
PURCHASE
—2" x 4" x lO' (2) Cut one piece into two parts A and one part C. For the other
piece, cut it into three parts B and one part C.
—2" x 4" x 8' (9) Cut each piece into the parts () One part D, one part D, parts (E,
l), part (E, l), parts (K, G), parts (K, G), parts (L, M, M), parts (L, M, M) and
parts (L, M, M)
—2" x 4" x lO' (1) Cut this piece into parts L, F, F and H.
—2" x 6" x 8' (1) Cut this piece into JI, J2 and J3.
—1" x 4" x 8' (1) Cut this for part O.
—1" x 4" x lO' (1) Cut this into one part 0 and one part N.
—1" x 6" x lO' (9) Shiplap. Cut each piece into three parts P, for a total of 27 pieces.
—1" x 6" x 8' (13) Shiplap. Cut each piece into two parts Q, for a total of 26 pieces.
—1" x 6" x 8' (6). Shiplap. Cut each piece into one part T.
—1" x 6" x 8' (1) Cut piece into three parts R.
—1" x 4" x 8' (1) Cut piece into two parts S.
APPENDIX H: LIGHTWEIGHT OUTHOUSE PLANS—177
H.4
Metal Roofing: 3' x 7' (2)
Roofing Screws (Minimum 30)
3" Screws (3 lbs. for privy and platform)
5d Galvanized box nails (1/2 lbs.)
1 1/4 Screws for assembling door; platform and cover hardware (50)
6" T-hinge for door (1 pair)
Handle (2), Hook and eye (2 pairs)
Toilet seat
Figure H.1—Plans for a lightweight outhouse. It can be used with a moldering privy, or
with a batch-bin or beyond-the-bin system when placed over a vault to hold the catcher
(see Chapter 7, the Batch-Bin System). This plan does not show a lift-up bench seat or
a rear access door, either of which makes it more convenient to inspect and manipulate the waste pile. Plans from Jeff Bostwick, Green Mountain Club.
HARDWARE
MISCELLANEOUS
178—APPALACHIAN TRAIL CONFERENCE —BACKCOUNTRY SANITATION MANUAL
Figure H.2
APPENDIX H: LIGHTWEIGHT OUTHOUSE PLANS—179
Figure H.3
180—APPALACHIAN TRAIL CONFERENCE —BACKCOUNTRY SANITATION MANUAL
Figure H.4
Figure H.5
I
Plans for a Double-Chambered
Moldering Privy
I.1
The screws used on this project are three inches long. The hardware cloth, fiberglass and metal roofing should be cut before heading out into the field (see steps 7,
9 and cover instructions, part 9). I would assemble both structures before going to
the site.
Platform
1. Cut material to length as shown on Materials list.
2. Take three of parts C and three of parts A, lay parts A across parts C as shown on
front view. Make sure the bottom course is one inch above the bottom of parts C.
This will allow for any uneven surface at the site. There also should be a one inch
overhang over the end parts C for parts B to butt into. The middle part C is
evenly spaced between the other two.
3. Make sure the spacing of parts A is as shown on the front view.
4. Take the other parts A and C and repeat steps 2 and 3.
5. Take six parts B and attach three parts to each end between the front and back
sections as shown on the side view. Then attach the remaining parts B to the two
middle parts C. The structure is now free standing.
6. Attach parts D and E to the top of the structure. The framing is now complete.
7. The next step is to cut the 3' x 25' hardware cloth into four nine inch wide strips.
A jigsaw with a metal blade is best for this.
8. Cut and attach the hardware cloth to both inside and outside of the openings of
the platform. Also attach it to both sides of the interior divider. A staple gun
works well for this.
PRIVY PLATFORM/COVER
182—APPALACHIAN TRAIL CONFERENCE —BACKCOUNTRY SANITATION MANUAL
9. Next take an 11 foot section of the fiberglass screening and cut if into four nine
inch wide sections. Staple this to the outside only of the openings.
10.Attach the joist hangers to the front of the structure where the privy will sit and
attach the stringers (F) to that. Then screw down the steps (G) to the stringers.
11.The last step is to attach the privy to the platform. Use the 2" L-brackets, keep
the privy two inches from the side edge and one inch from the front and back.
Cover
I. Take a 2" x 8" x 8' and cut into two pieces, one 46 inches long, the other 38 3/4
inches long.
2. With the 46 inch piece measure 1 1/4 inches in width from one edge and 1 1/4
inches in width from the other end and opposite edge. When you connect the
two points, there will be a diagonal line (see Parts close up). Cut along this line
so that you have two equal parts that look like part H. The angle on this diagonal
will be around six degrees.
3. With the 38 3/4 inch section, measure 1 1/4 inches wide along its length. Set
your saw to approximately six degrees and make a bevel cut, this will result in
part J (see Parts close up). Make sure the width is 1 1/4 inches. The remaining
piece (I) will have the same angle and have a maximum width of around six
inches. These parts should match up with the ends of parts H as shown on the
side view.
4. With part I, a notch will be cut so that it slides under the exterior sheathing of
the privy. This notch will measure 3/4” x 3 1/2" (see front view). Make sure that
this is cut into the correct end. See Front view.
5. With both parts H, cut a 1 1/2" x 3 1/2" notch 13 inches from each end into the
top edge. This notch will accept parts K.
6. Screw parts H between parts I and J. Make sure they are placed in the positions
shown on the front view.
7. Secure the frame to the platform with the mending strips, the frame should be
flush with the outside edges of the platform.
8. Screw parts K into the notches on parts H.
9. Lastly, cut the metal roof to 51 1/4 inches and attach to the frame. Leave a one
inch overhang over the front and back edges.
I.2
MATERIALS LISTPLATFORM/COVER
All wood for the platform and cover is pressure treated.
A. 5/4" x 6" x 72" (6)
B. 5/4" x 6" x 47" (9)
C. 4" x 4" x 29 1/2" (6)
D. 2" x 4" x 72" (2)
APPENDIX I: PLANS FOR A DOUBLE-CHAMBERED MOLDERING PRIVY—183
E. 2" x 4" x 42" (3)
F. 4-Step stringer (2)
G. 2" x 8" x 32" (3)
H. 2" x 6" x 46" (2)*
I. 2" x 6" x 38 3/4" (1)*
J. 2" x 1 1/4" x 38 3/4" (1)*
K. 2" x 4" x 38" (2)
* Overall size
—5/4" x 6" x 10' (6) Take the six pieces and cut each into one part A and one part B.
I.3
—5/4" x 6" x 12' (1) Cut this piece into three parts B.
RECOMMENDED WOOD
TO PURCHASE
—4" x 4" x 8' (2) Cut each piece into three parts C.
—2" x 4" x 10' (3) Take two pieces and cut each into one part D and one part E.
The third piece can be cut into one part E and two parts K.
—2" x 8" x 8' (2) Cut the first piece into parts H and parts I and J. The second piece
can be cut into three parts G.
Metal roofing: 3' x 5' (1)
Roofing Screws (20)
2" L-Brackets (2 pair) and screws
2" x 8" Joist Hangers (2)
3' x 25' 1/4" Hardware Cloth
3' x 15' Fiberglass Screening (for privy and platform)
Staples
3" Mending strips (4)
I.4
HARDWARE/
MISCELLANEOUS
184—APPALACHIAN TRAIL CONFERENCE —BACKCOUNTRY SANITATION MANUAL
Figure I.1—Plans for the construction of the latest prototype of the Green Mountain Club moldering privy, a double-chambered design. Plans from of Jeff Bostwick, Green Mountain Club.
APPENDIX I: PLANS FOR A DOUBLE-CHAMBERED MOLDERING PRIVY—185
Figure I.2
J
Plans for a Drying Rack
Bill of Materials
Notch 3/4 inch PT Ply. Deck
3 inch x4 inch @ corners type.
Post fillers (2x4)
typ. @ corners
2 PC — 2 x 4 x 8 foot pres. treat. (posts)
3 PC — 2 x 4 x 12 foot SPF (rails, rafters)
5 PC — 2 x 4 x 8 foot SPF (end rails, joists, fillers)
1 PC — 4 x 8 foot — 3/4 inch pres. treat. ply (deck)
2 PC — 4 x 8 foot — 1/2 inch cdx ply (ends, back)
2 PC — 38 inches wide x 54 inches long Galv. Channel Drain Roof
2 lbs. — 3 inch deck screws
1 lbs. — 11/2 inch deck screws
1 lbs. — 11/2 inch galv. Roof screws
APPENDIX J: PLANS FOR A DRYING RACK—187
Figure J.1—Diagram of the Green Mountain Club’s drying rack, used with their batch-bin and beyond-the-bin and moldering
privy systems.” Diagram from Eric Seidel and the Green Mountain Club.
K
Diagram of a Washpit
A washpit is composed of a 12" deep hole filled with rocks of varying sizes. It is best
to place smaller rocks and gravel towards the bottom of the pit and larger rocks
towards the top. On the top of the pit is a wooden frame covered with hardware
cloth and screen. This filter will prolong the life of the pit and allow people to pack
out their food waste. If you can’t dig a 12" deep hole, you will have to construct a
runway that leads to a second pit or consider using a designated dishwashing area
(see Section 13 for more info).
Figure K.1—Green Mountain Club style washpit. Drawing from the Green Mountain
Club.
L
Backcountry Sanitation: A Review of
Literature and Related Information
By Paul R. Lachapelle, Volunteer, Green Mountain Club
L.1
Sanitation issues associated with recreational activities are often difficult to resolve,
particularly in cold climates. Managers and users need information, but literature
on sanitation in backcountry settings is scarce, and information on sanitation is
often hidden in general outdoor and recreation-related literature.This chapter provides a review of literature, case studies, proceedings and related works dealing with
sanitation as it applies to recreation and backcountry use, and presents a chronicle
of related research on water quality, recreation and sanitation infrastructure.
INTRODUCTION
L.2
Backcountry sanitation research began in the mid 1970’s in response to increased
visitation at backcountry sites with low assimilative capacity for human waste. Researchers under the direction of the U.S. Forest Service (USFS) Northeastern Forest Experiment Station in Durham, NH, began to investigate methods of treating
and disposing of human waste on-site using a batch (also termed bin or thermophilic) composting system.
Some of the earliest studies, including the work of Fay and Walke (1977), Ely and
Spencer (1978), Leonard and Fay (1978), Fay and Leonard (1979) and Plumley and
Leonard (1981) detail the batch composting method using a fiberglass-covered plywood bin intersected with perforated PVC (polyvinyl chloride plastic) tubes to increase aeration. The technique used in these early trials was adopted at many sites
in New England, and has remained a viable method for managing high volumes of
human waste in the backcountry. Contemporary bin composting systems often use
high-density plastic containers and liquid treatment devices detailed later in this
chapter.
Early studies established that, “(A) bark-sewage mixture can be composted to produce a pathogen-free substance “ (Fay and Walke 1977:1) in which “(T)he final
THE EARLIEST RESEARCH
190—APPALACHIAN TRAIL CONFERENCE —BACKCOUNTRY SANITATION MANUAL
product of the compost process is a dark brown, humus-like substance that can be
scattered on the forest floor” (Fay and Leonard 1979:37-38).
Leonard and Fay (1978:6) said the composting process was “...as much an art as it is
a science,” explaining, “(T)he temperature of a compost pile is probably the best
indicator of good, aerobic composting.”
Ely and Spencer (1978:9) tested the end-product from the batch composting system
and found that “...enteric disease-causing organisms (which generally occur in smaller
numbers) [sic] could also survive the compost process,” and further refined the process by incorporating a drying rack to make the end product safer. “(T)o obtain an
end product containing little or no enteric organisms, a six to twelve month holding period is recommended. ...(H)igh pile temperatures are not a guarantee that
each and every undesirable organism has been sufficiently exposed to a fatal wet
heat. For this reason, composted material should be handled with care at all times.”
Leonard and Plumley of the USFS (1979:351, 352) detail the use of both batch
composters and a Clivus Multrum continuous composting toilet at several sites in
the White Mountain National Forest in New Hampshire. They comment,
“(C)omposting systems may be cheaper than the fly-out system or chemical toilets.
...A comparison of total costs over a period of 10 years indicates that composting
can be cheaper than other methods despite the additional maintenance time required.”
The authors concluded that the batch system offered numerous advantages to other
human waste treatment and disposal systems: (1) batch systems are effective in reducing (but not necessarily eliminating) both the volume and pathogenic characteristics of human waste; (2) batch systems can be utilized at diverse backcountry
locations; and (3) batch systems offer a cost-effective and economical method of
human waste disposal at backcountry sites.
Cook, (1981) also of the USFS, began research of composting toilets in the same
period, and described and evaluated the use of 33 bin composters and continuous
composting toilet systems in five backcountry locations in the United States. After
laboratory tests of fecal coliform content of the end-product from these toilets, Cook
(1981:95) found that “(N)either bin nor continuous composting was capable of
reducing fecal coliforms to recommended levels,” but added, “(I)f the waste after
composting can be shallow buried at or near the site [and] results in no detrimental
health effects to the public, then perhaps the system of composting can be considered in selected areas.”
Passive solar-assisted continuous composting toilet have been used in numerous locations. Franz (1979) and Ely and Spencer (1978) document the use of a Soltran
model continuous composting system using large solar panels and an insulated heat
storage area to aid the composting process at several sites in the White Mountains
of New Hampshire. These units have since been removed because of the expense of
installation and maintenance, and their failure to accelerate composting.
Leonard and others (1981) detail sanitation techniques at backcountry sites, including individual disposal, pit toilets, haul-out systems, chemical toilets, advanced
composting systems and waterborne waste disposal using filtration and spray disposal systems.
APPENDIX L: REVIEW OF LITERATURE AND RELATED INFORMATION—191
L.3
The National Park Service (NPS) began an active research program in the mid
1980s with the investigation of a dehydrating system and nine Clivus Multrum continuous composting systems in “remote sites that lack power, water, soil depth and
vehicle access” in several national parks in the United States (Jensen 1984:1-1).
The report states that “(A)ll the compost toilets were found to require a liquid
disposal system ...None of the ventilation systems were operating as designed ...Compost systems operating at less than 50% of the recommended loading rate appeared
to function with a minimum, or no attention to the process [and] ...None of the
units demonstrated the sliding of the solid material on the inclined bottom of the
tank.” (Jensen 1984:1-1). The dehydrating toilet detailed in the report is a Shasta
model and “...required modifications to provide satisfactory performance, [since]
drying the large accumulation of solids was not successful” (Jensen 1984:1-2).
The National Park Service also commissioned a study and report on the use of nine
batch composting system in North Cascades National Park in Washington (Weisburg
1988) to determine the feasibility of this technique in high-use humid environments.
Further refinement of the batch system was conducted by the Green Mountain Club
in Vermont, which coordinated four editions of the “Manual for Bin Composting
and Waste Management in Remote Recreation Areas” beginning in 1977, and most
recently updated by Pete Ketcham, Field Supervisor of the Green Mountain Club,
as part of this Backcountry Sanitation Manual (2001). This edition details the compost process, the operation of the batch system and troubleshooting techniques. It
includes schematics of the composting bin, drying rack and outhouse structure, and
lists suppliers of plastic bins useful for composting.
Additional refinements to the batch system include the availability of a commercial
bin manufactured by Romtec employing a small solar glazing to increase passive
solar gain (Drake 1997). Refinements to continuous composting systems include
Phoenix composters with tines to mix waste (Land 1995 a) and Bio-Sun Systems
continuous composting toilets with large access doors and geotextile fabric to support waste above the floor of the chamber to increase aeration (Lachapelle 1996).
Increasing backcountry use also prompted research relating on the breakdown of
fecal coliform and other bacteria using the “cathole” method. Temple and others
(1982:357), in their study of shallow catholes in the Bridger Mountains of Montana, “disappointingly” found that even after a year, “(B)acterial numbers remained
on a plateau [meaning pathogen levels had not significantly decreased and] ...Depth
of burial made no difference.”
In the 1980s numerous empirical studies were conducted on water quality in
backcountry recreation settings (Silsbee and Larson 1982; Tunnicliff and Brickler
1984; Carothers and Johnson 1984; Bohn and Buckhouse 1985; Suk and others
1986; Flack and others 1988; Aukerman and Monzingo 1989). These studies document bacterial contamination of backcountry surface water, the increase of giardiasis in backcountry waters and methods of examining and quantifying water quality.
They reinforced the importance of hygienic behavior in the backcountry.
Solar dehydration has been investigated as a potential backcountry sanitation method
by the Forest Service and the Park Service. It has been used with varying success on Mt.
Whitney in California (McDonald and others 1987) and in Mt. Rainier National Park
in Washington (Drake 1997). In addition, the surface water runoff from the dehydrating
toilet at Mt. Rainier was tested by Ells (1997), who was not able to document water
contamination. However, the dehydrated end product from these toilets is often high in
pathogens, difficult to handle and cannot be disposed of on-site.
DEVELOPMENT OF
METHODS AND RESEARCH
192—APPALACHIAN TRAIL CONFERENCE —BACKCOUNTRY SANITATION MANUAL
L.4
WORKSHOPS AND
PROCEEDINGS
Numerous conferences and workshops have focused either peripherally or specifically on waste management options in the backcountry. The Alpine Club of Canada
(ACC) held the symposium “Water, Energy and Waste Management in Alpine
Shelters” in 1991 at Chateau Lake Louise, Alberta, the first meeting on backcountry
waste management. The proceedings describe waste management technologies at
various ACC backcountry sites, including septic and gray water systems, fly-out
systems and incineration systems (Jones and others 1992).
The “Backcountry Waste Technology Workshop” held March 30-31, 1993, at Mt.
Rainier National Park in Washington hosted about 25 participants from Canadian
and United States organizations. It considered professional experiences with pit
and vault toilets, composting, dehydration, and fly-out and carry-out techniques
(Mt. Rainier National Park 1993). Workshop participants identified a need for a
document covering design considerations for backcountry waste systems and a need
to give higher priority to management of and budgeting for human waste. The agenda
was continued the following year in Yosemite National Park in California with a
workshop that resulted in a document on continuous composting toilets and issues
of compliance, design, construction, operation and maintenance (Yosemite National
Park 1994).
The conference “Environmental Ethics and Practices in Backcountry Recreation”
in Calgary, Alberta, in 1995, sponsored by the Alpine Club of Canada, contained a
session on backcountry waste management, and produced a proceedings of conference papers (Josephson 1997). The proceedings contain an analysis by Drake (1997),
who documents the use of a “blue bag” policy for an individual pack-out requirement on several of the popular climbing routes of Mt. Rainier. Drake reports that
compliance is much lower than expected.
Most recently, the Australian Alps Best Practice Human Waste Management Workshop was held in Canberra, Australia, March 27-31, 2000, hosted by the Australian
Alps National Parks. The proceedings contain more than 30 papers covering such
subjects as personal carry-out techniques using “pootubes,” and accounts from site
managers in Australia and New Zealand of on-site and off-site treatment and disposal techniques including composting, septic and vermiculture systems (which use
worms to aid decomposition of waste) (Australian Alps National Parks 2000).
L.5
CURRENT STATE OF
KNOWLEDGE
Recent research on perceptions of backcountry waste issues reveals that 25 percent
of National Park Service managers find human waste to be a common problem in
many or most areas, and 43 percent consider it a serious problem in a few areas
(Marion and others 1993). In their study of social and ecological normative standards, Whittaker and Shelby (1988) found that the standard for human waste represented a no-tolerance norm, in which 80 percent of the respondents reported that
it was never acceptable to see signs of human waste.
Voorhees and Woodford (1998) document the recent controversy over the expense
of several continuous composting toilets in Delaware Water Gap National Recreation Area in New Jersey and Pennsylvania and in Glacier National Park in Alaska.
The authors argue that although the project was widely criticized, by using environmentally-sensitive materials the structure actually minimized the life-cycle cost of
the facility (Voorhees and Woodford 1998:63).
APPENDIX L: REVIEW OF LITERATURE AND RELATED INFORMATION—193
Further refinements of bin composting have been investigated by the Appalachian
Mountain Club White Mountain Trails Program with funding from the Appalachian Trail Conference and the National Park Service. The resulting document
describes the “Beyond the Bin Liquid Separation System” used to treat excess liquid
from the standard batch-bin composting system (Neubauer and others 1995).
The U.S. Forest Service has continued its commitment to an active research program, particularly through its Technology and Development Center in San Dimas,
California, including two documents by Land (1995a,b) describing various bin and
continuous composting toilets and other remote waste management techniques.
In addition, the Aldo Leopold Wilderness Research Institute has been active in
research on visitation management and low-impact recreational practices, including sanitation in federally designated Wilderness in the US (Cole 1989; Cole and
others 1987). Lachapelle (2000) examines human waste treatment and disposal
methods in designated Wilderness, and supplies a decision-making matrix and flow
chart to help managers consider the pros and cons of various backcountry waste
management techniques and their social and biophysical implications.
It is now possible to use DNA testing to reveal the sources of fecal coliform colonies
in backcountry water sources. This technique has been used to document human
fecal contamination in high-use backcountry areas of Grand Teton National Park
in Wyoming (Tippets 1999, 2000).
Studies directed by the USFS examine the use of a passive solar device to further
treat and inactivate the end product of composting toilets. These studies indicate
that a solar “hot box” can pasteurize compost and save transport and disposal costs,
while providing more safety for field personnel (Lachapelle and Clark 1999;
Lachapelle and others 1997).
Most recently, Cilimburg and others (2000) have produced a comprehensive examination of various backcountry waste management practices with a focus on past
studies of the pathologies of water contamination and their implications for recreational activities.
Many books describe commercial composting toilets and other methods of disposal
and treatment of human waste in the backcountry. These include the books by Meyer
(1994), who explores anecdotal and often amusing accounts of handling human
waste in the backcountry; Hampton and Cole (1995), who describe waste treatment and disposal techniques in a variety of environmental situations; Del Porto
and Steinfeld (2000), who detail choosing and planning a composting toilet systems with a focus on commercial systems and related state statutes; and Jenkins
(1999), who describes a more homemade approach to batch composting.
L.6
Books
Del Porto, D. and C. Steinfeld. 2000. The Composting Toilet System Book: A Practical
Guide to Choosing, Planning and Maintaining Composting Toilet Systems, a WaterSaving, Pollution-Preventing Alternative. Concord, MA: Center for Ecological Pollution Prevention. 235 p.
Hampton, B. and D.N. Cole. 1995. Softpaths: How to Enjoy the Wilderness Without
Harming it. Mechanicsburg, Pa.: Stackpole Books. 222 p.
LITERATURE CITED
194—APPALACHIAN TRAIL CONFERENCE —BACKCOUNTRY SANITATION MANUAL
Jenkins, J. 1999. The Humanure Handbook: a Guide to Composting Human Manure.
(2nd ed.). Grove City, Pa.: Jenkins Publishing. 302 p.
Meyer, K. 1994. How to Shit in the Woods: an Environmentally Sound Approach to a
Lost Art. (2nd ed.) Berkeley: Ten Speed Press. 107 p.
Journals
Aukerman, R. and D.L. Monzingo. 1989. “Water treatment to inactivate Giardia.”
Journal of Forestry. 87: 18-21.
Bohn, C.C., and J.C. Buckhouse. 1985. “Coliforms as an indicator of water quality
in wildland streams.” Journal of Soil and Water Conservation. 40: 95-97.
Carothers, S.W. and R.A. Johnson. 1984. “Recreational impacts on Colorado river
beaches in Glen Canyon, AZ.” Journal of Environmental Management. 8(4): 353358.
Cilimburg, A., C. Monz and S. Kehoe. 2000. “Wildland recreation and human waste:
a review of problem, practices, and concerns.” Environmental Management. 25(6):
587-598.
Ells, M.D. 1997. “Impact of human waste disposal on surface water runoff: the Muir
snowfield, Mount Rainier.” Journal of Environmental Health. 59(8): 6-13.
Fay, S. and R. Leonard. 1979. “Composting privy wastes at recreation sites.” Compost Science/Land Utilization. 20(1): 36-39.
Flack, J.E., A.J. Medine, and K.J. Hansen-Bristow. 1988. “Stream water quality in a
mountain recreation area.” Mountain Research and Development. 8(1): 11-22.
Franz, M. 1979. “Four backcountry composters.” Compost Science/Land Utilization.
20(4): 38-39.
Lachapelle, P.R. and Clark, J.C. 1999. “The application of a solar ‘hot box’ to pasteurize toilet compost in Yosemite National Park.” Park Science. 19(1): 1.
Lachapelle, P.R., B. Land and J.C. Clark. 1997. “The problem of human waste disposal in national parks: a solar energy experiment in Yosemite National Park,
California, USA.” Mountain Research and Development. 17(2): 177-180.
Leonard, R.E.,and H.J. Plumley. 1979. “Human waste disposal in eastern
backcountry.” Journal of Forestry. 77(5): 349-352.
Plumley, H.J. and R.E. Leonard. 1981. “Composting human waste in remote recreation sites.” Parks. 8(1): 18-21.
Silsbee, D.G. and G.L. Larson. 1982. “Bacterial water quality: springs and streams
in the Great Smoky Mountains National Park.” Environmental Management. 6(4):
353-359.
Temple, K., A. Camper and R. Lucas. 1982. “Potential health hazards from human
wastes in wilderness.” Journal of Soil and Water Conservation. 37(6): 357-359.
Tunnicliff, B. and S.K. Brickler. 1984. “Recreational water quality analyses of the
Colorado River Corridor in Grand Canyon.” Applied and Environmental Microbiology. 48(5): 909-917.
APPENDIX L: REVIEW OF LITERATURE AND RELATED INFORMATION—195
Voorhees, P. and E. Woodford, 1998. “NPS and the $300,000 privy: a parable for
management.” The George Wright Forum. 15(1): 63-67.
Whittaker, D. and B. Shelby. 1988. “Types of norms for recreation impacts: extending the social norms concept.” Journal of Leisure Research. 20(4): 261-273.
Proceedings
Australian Alps National Parks. 2000. “Australian Alps Best Practice Human Waste
Management Workshop Proceedings.” Canberra, Australia: Australian Alps National Parks.
Cook, B. 1981. “Field evaluation of composting toilets.” In: N.I. McClelland and
J.L. Evans (eds.), Individual On-Site Wastewater Systems: Proceedings of the 7th
National Conference. Ann Arbor, MI: National Sanitation Foundation: 83-98.
Drake, R. 1997. “Backcountry human waste disposal at Mount Rainier National
Park.” In: Josephson J. (ed.) Environmental Ethics and Practices in Backcountry
Recreation. Canmore, Alberta: Alpine Club of Canada: 21-24.
Jones, T., C. Hannigan, M. Mortimer and D. Thompson (eds.). 1992. Water, Energy
and Waste Management in Alpine Shelters Symposium: Notes from a Canadian Conference. Oct. 27-28, 1991, Chateau Lake Louise, Alberta. Canmore, Alberta:
Alpine Club of Canada. 205 p.
Josephson J. (ed.). 1997. Environmental Ethics and Practices in Backcountry Recreation. Canmore, Alberta: Alpine Club of Canada. 131 p.
Lachapelle, P.R. 2000. “Sanitation in wilderness: balancing minimum tool policies
and wilderness values.” In: D.N. Cole, S.F. McCool, W.T. Borrie and J. O’Loughlin
(comps.) Wilderness Science in a Time of Change Conference—Volume 5 Wilderness
Ecosystems, Threats, and Management; 1999 May 23-27; Missoula, MT. Proc.
RMRS-P-0-VOL-5. Ogden, UT: U.S. Department of Agriculture, Forest Service,
Rocky Mountain Research Station.
Suk, T.J., J.L. Riggs and B.C. Nelson. 1986. “Water contamination with Giardia in
back-country areas.” In: Proceedings of the National Wilderness Research Conference: Current Research. General Technical Report INT-212. Ogden, UT: U.S. Department of Agriculture, Forest Service, Intermountain Research Station: 237244.
Government Publications
Cole, D.N. 1989. “Low-impact Recreational Practices for Wilderness and
Backcountry.” Gen. Tech. Rep. INT-265. Ogden, UT: U.S. Department of Agriculture, Forest Service, Intermountain Research Station. 131 p.
Cole, D.N., M.E. Peterson and R.C. Lucas. 1987. “Managing Wilderness Recreation Use: Common Problems and Potential Solutions.” Gen. Tech. Rep. INT230. Ogden, UT: U.S. Department of Agriculture, Forest Service, Intermountain Research Station. 60 p.
Fay, S. and R. Walke. 1977. “The Composting Option for Human Waste Disposal in
the Backcountry.” Forest Service Research Note NE-246. Broomall, PA: U.S. Department of Agriculture, Forest Service, Northeastern Forest Experiment Station. 3 p.
196—APPALACHIAN TRAIL CONFERENCE —BACKCOUNTRY SANITATION MANUAL
Jensen, M.E. 1984. “National Park Service Remote Area Toilet Facilities: Experiences and Observations, 1983 and 1984.” NPS Report No. 85-01-NPS/ESSD.
Washington, DC: Department of the Interior, National Park Service, Environmental Sanitation Program. 718 p.
“Land, B. 1995a. Composting Toilet Systems: Planning, Design, and Maintenance.”
Tech. Rep. SDTDC 9523-1803. San Dimas, CA: U.S. Department of Agriculture, Forest Service, Technology and Development Program. 38 p.
Land, B. 1995b. “Remote Waste Management.” Tech. Rep. SDTDC 9523-1202. San
Dimas, CA: U.S. Department of Agriculture, Forest Service, Technology and
Development Program. 31 p.
Leonard, R. and S. Fay. 1978. “A Compost Bin for Handling Privy Wastes: Its Fabrication and Use.” Forest Service Research Note NE-254. Broomall, PA: U.S. Department of Agriculture, Forest Service, Northeastern Forest Experiment Station. 6 p.
Marion, J.L., J.W. Roggenbuck, R.E. Manning. 1993. “Problems and Practices in
Backcountry Recreation Management: a Survey of National Park Service Managers.” Natural Resources Report NPS/NRVT/NPR.93/12. Denver, CO: U.S. Department of the Interior, National Park Service, Natural Resources Publication
Office. 65 p.
McDonald, J., R. Stanley and D. McCauley. 1987. “Mount Whitney solar toilet.”
U.S. Department of Agriculture, Forest Service, Engineering Field Notes. 19: 13-19.
Yosemite National Park. 1994. Backcountry Human Waste Management: A Guidance
Manual for Public Composting Toilet Facilities. U.S. Department of Interior, National Park Service, Yosemite National Park. 83 p.
Manual
Davis, B. and P. Neubauer. 1995. Manual for Bin Composting and Waste Management
in Remote Recreation Areas. (4th ed.) Waterbury Center, VT: Green Mountain
Club. 68 p.
Pamphlets
Ely, J. and E. Spencer. 1978. The Composting Alternative: Waste Management in Remote Locations. Gorham, NH: Appalachian Mountain Club. 28 p.
Neubauer, P., P. Cunha and N. Hall. 1995. A Study of System Improvements to Traditional Batch Composting. Appalachian Mountain Club, White Mountain Trails
Program. 25 p.
Newsletter
Lachapelle, P.R. 1996. “New slant on composting-toilet technology.” The Register,
19(2): 10. Appalachian Trail Conference.
Unpublished Reports
Mount Rainier National Park. 1993. “Backcountry Toilet Technology Workshop.”
Unpublished report. Ashford, WA: U.S. Department of the Interior. National
Park Service, Mount Rainier National Park.
APPENDIX L: REVIEW OF LITERATURE AND RELATED INFORMATION—197
Tippets, N. 1999. “Backcountry Water Quality Testing in Grand Teton National
Park, 1998 Summer Season.” Unpublished report. Moose, WY: U.S. Department
of the Interior, National Park Service, Grand Teton National Park.
Tippets, N. 2000. “Backcountry Water Quality Testing in Grand Teton National
Park, 1999 Summer Season.” Unpublished report. Moose, WY: U.S. Department
of the Interior, National Park Service, Grand Teton National Park.
Weisburg, S. 1988. “Composting Options for Wilderness Management of Human
Waste.” Unpublished report. Rep. No. K70172. Sedro Wooley, WA: U.S. Department of the Interior, National Park Service, North Cascades National Park,
Skagit District. 57 p.
Editor's Note:
M
This article was originally published in Park Science, a resource
management bulletin of the National Park Service, under the citation:
Lachapelle, P. R., and J. C. Clark, 1999. The application of a solar "Hot
Box" to pasteurize toilet compost in Yosemite National Park. Park Science
19(1): 1, 20-21, and 24.
The Application of a Solar Hot Box
To Pasteurize Toilet Compost
In Yosemite National Park
November 11, 1998
Paul R. Lachapelle, John C. Clark
Land managers today are continually searching for sustainable backcountry management techniques while decreasing operational expenditures and the use of human resources. The public is also increasingly concerned about expedient backcountry
infrastructure projects including the construction of innovative toilet facilities
(Voorhees & Woodford, 1998). Past research has documented composting toilet
technologies as a low-cost, efficient and sustainable method of backcountry human
waste treatment (Davis & Neubauer, 1995; Land, 1995 a,b; Yosemite NP, 1994;
Mount Rainier NP, 1993; Weisberg, 1988; McDonald et al. 1987; Jensen, 1984;
Cook, 1981; Leonard et al., 1981).
While considerable research has demonstrated the operation and maintenance of
composting toilets in the backcountry, few studies have explored proper methods of
composting toilet end-product disposal. In 1996, the USDA Forest Service, San
Dimas Technology and Development Center and the USDI National Park Service,
Yosemite National Park, conducted a cooperative study in the development and
operation of a passive solar insulated box (termed the “Hot Box”) to treat the endproduct from composting toilets used by hikers in the backcountry. The study demonstrated that the Hot Box could consistently meet U.S. Environmental Protection
Agency heat treatment requirements and produce a class A sludge that could be
surface-applied as outlined in 40 Code of Federal Regulations (CFR) Part 503
(Lachapelle et al. 1997). According to the regulation, this heat treatment is a function of time and temperature.
APPENDIX M: APPLICATION OF A SOLAR HOT BOX—199
The study demonstrated that the time-temperature requirement could consistently
be met in Yosemite NP, an area that proved ideal because of high ambient air temperatures and consistent sunlight throughout much of the summer.
Field staff at Yosemite NP tested the application of the Hot Box to pasteurize large
quantities of end-product during the summers of 1997 and 1998. Field staff report
that the Hot Box operated well and required minimal labor under optimal conditions.
All of the end-product removed from backcountry toilets in Yosemite NP was previously sealed in plastic bags, deposited into designated dumpsters and then thrown
away in a local landfill. The end-product is now surface-applied out of the park in
local flower gardens near the park headquarters in El Portal.
Background
The development of backcountry composting toilet methods resulted from the need
to reduce impacts including surface water pollution at overnight sites. Research of
backcountry composting systems began in the mid-1970’s and focused on sites with
up to 2,000 overnight visitors per season (Fay & Walke, 1977; Ely & Spencer, 1978).
Composting technologies became increasingly popular as research documented the
ineffective break-down of coliform bacteria using the “cat-hole” disposal technique
(Temple et al. 1982) and as certain composting toilet technologies were shown to
be a low-cost solution for human waste treatment and disposal (Leonard & Fay,
1979; Leonard & Plumley, 1979). Thermophilic composting (also termed batch or
bin) and mesophilic composting (also termed moldering or continuous) have been
used with varying degrees of success in numerous National Parks (Yosemite, Mt.
Rainier, Olympic, Grand Canyon) and National Forests (White Mountain, Green
Mountain).
The aim of any composting technology is to optimize conditions for microbial growth.
Combining the proper amount of carbon (also termed bulking agent and usually
consisting of woodchips or shavings), moisture, ambient heat and oxygen enhances
the living conditions within the compost pile for natural oxygen-using microorganisms (aerobes). These aerobes use human waste as a food source and consequently,
the waste decomposes over time into a soil-like substance. Disease-causing organisms (pathogens) within the human waste are reduced or eliminated due to competition, natural antibiotics, nutrient loss and heat.
The human waste and the carbon are in most cases manually mixed in an enclosure
or sealed bin. The term end-product refers to the composted woodchips and human
waste. The composting process functions optimally with a carbon to nitrogen ratio
of 25-35:1 and a moisture content of 60% (Davis & Neubauer, 1995).
The aim of thermophilic composting, which requires frequent mixing (several mixes
per week) and high woodchip input (approximately 1 kg of carbon to 1 liter of
human waste), is to kill pathogens quickly and with hot temperatures. These temperatures result from microbial activity and can exceed 45 degrees C. Once a sufficient amount of human waste has been collected, a compost “run” is started and can
take up to several weeks to complete.
Mesophilic composting in comparison is a long-term method that can take years to
effectively reduce pathogens within the waste. Additionally, the frequency of mixing and the amount of carbon added are considerably lower than thermophilic methods with temperatures within the waste pile ranging between 10 degrees C to 45
degrees C.
200—APPALACHIAN TRAIL CONFERENCE —BACKCOUNTRY SANITATION MANUAL
However, complete pasteurization of composting toilet end-product by either treatment method can never be guaranteed and depends on the quality of maintenance
and site conditions. Heat treatment, such as the Hot Box can provide, is one method
to ensure pathogen reduction and meet 40 CFR Part 503. Consequently, the Hot
Box can help in a number of ways.
First, if land management policy dictates that the end-product can be surface-applied at the backcountry toilet site, significant savings in transportation costs could
result. Additionally, the biophysical and social impacts from using either pack animals or helicopter resources could be reduced.
Second, while land management policy may dictate that the end-product be transported outside of a protected area boundary, heat-treated compost is less of a health
and safety issue to field staff. Since, for example, a fundamental tenet of the Wilderness Act states that the wilderness area be “protected and managed so as to preserve
its natural conditions” (Wilderness Act of 1964, Sec 2c), surface-applied compost
in these areas could be problematic. Unquestionably, increased nutrient levels resulting from on-site disposal could upset natural species assemblages by shifting the
competitive advantage to invasive non-native plant species. However, end-product that is heat-treated in the backcountry would be a considerably lower health
hazard to field staff regarding accidental spillage during transport or disposal.
Third, if the end-product cannot be surface-applied at the site and the Hot Box
cannot be used in the field because of staffing or ordinance issues, landfill disposal
savings could result.
Lastly, the treated end-product could be reintroduced into the composting toilets as
bulking agent which would reduce the amount of additional bulking agent needed.
Hot Box Description and Application
The Hot Box is a nearly air-tight container that allows the sun’s short-wave radiation or light energy to pass through the glazing. The contents of the Hot Box absorb
the light energy and convert it to long-wave radiation or heat energy which becomes trapped inside the box.
The 1996 USFS/NPS study demonstrated that temperatures of over 100 degrees C
(212 degrees F) can be reached and temperatures of 88 degrees C (190 degrees F)
can be sustained for several hours.
The outside walls, floor and removable tray are fabricated from an approximately .5
cm thick aluminum sheet. A single transparent Lexan® Thermoclear polycarbonate sheet is used as the solar glazing and is bolted at an angle specifically designed to
maximize the angle of incidence during the summer solstice for the chosen latitude
(at Yosemite NP, 38 degrees north latitude, a 15 degree angle was chosen). This
angle could be adjusted for other locations. The inside walls and floor are insulated
with 5 cm poly-isocyanurate closed-cell foam. A door is positioned at the back of
the Hot Box in order to gain access to the tray. The original Hot Box measured 122
cm x 94 cm x 69 cm at the highest end and 46 cm at the lowest end.
Four new Hot Box’s, measuring 122 cm x 122 cm x 61 cm at the highest end and 20
cm at the lowest end have recently been built and appear to be more efficient because of their larger glazing and decreased internal air volumes.
Yosemite NP field staff operated the Hot Box during the 1997 and 1998 summer
seasons at the park headquarters in El Portal. Yosemite contains 6 backcountry
composting toilets that collectively produce approximately 20 cubic meters (700
APPENDIX M: APPLICATION OF A SOLAR HOT BOX—201
cubic feet) of end-product. Since most of the backcountry composting toilets are
located in federally designated wilderness areas, the end-product has been transported outside of the boundaries. End-product is transported in double plastic bags
by pack animals to trailheads and then trucked to El Portal. Approximately 9 cubic
meters (300 cubic feet) was pasteurized in 1998. Field staff emptied a portion of the
bags into the Hot Box tray and allowed the compost to pasteurize for up to one
week. It took one operator one-half hour per day two days per week to process approximately one cubic meter (30 cubic feet) of end-product.
The 1996 USFS/NPS study concluded that end-product pile depths in the tray of
12 cm or less and two and one-half hours of direct sunlight with ambient air temperatures exceeding 28 degrees C (83 degrees F) were most effective at meeting the
time-temperature requirement. Additionally, a moisture content of 60 percent or
less allowed for maximum temperature attainment.
Field staff would mix the end-product in the Hot Box tray several times during the
heat-treatment process to ensure thorough pasteurization. After pasteurization, the
finished compost was again bagged and brought to local flower gardens and spread
thinly on the surface. Operators reported that the pasteurized compost resembled
mulch and not human waste in both texture and odor and was therefore more tolerable to work with.
Conclusion
The passive solar Hot Box has been used for two field seasons in Yosemite NP, a
location shown to be ideal to effectively pasteurize the compost from backcountry
toilets. This application stems from the 1996 USFS/NPS study that demonstrated
the use of the Hot Box as an effective method of composting toilet end-product
pasteurization. Field staff report that the developed Hot Box technology required a
minimum level of attention and maintenance by the operator and produced a compost that is dryer and appears less offensive to handle and transport. It is anticipated
that further use of the Hot Box will refine design and performance imperfections.
While stringent regulations may negate the possibility that finished compost be
surface-applied in wilderness and national park areas, the Hot Box holds tremendous potential to save either transportation costs and associated impacts in areas
where the end-product can be surface-applied on-site, or disposal costs where the
end-product must be transported and disposed off-site. Conceivably, this passive
technology can serve as a sound and sustainable backcountry management technique, alleviating impacts, costs and extensive use of human and animal resources
while providing an added safety margin to field personnel.
Literature Cited
Cook, B. 1981. “Field evaluation of composting toilets.” In: N. I. McClelland & J.
L. Evans (Ed.), Individual on-site wastewater systems: proceedings of the seventh national conference. (pp. 83-98). Ann Arbor: National Sanitation Foundation.
Davis, B., & Neubauer, P. 1995. Manual for bin composting and waste management in
remote recreation areas. (4th ed.). Waterbury Center, Vt.: Green Mountain Club.
Ely, J., & Spencer, E. 1978. The composting alternative: waste disposal in remote locations. Gorham, N.H.: Appalachian Mountain Club.
Fay, S., & Walke, R. 1977. “The composting option for human waste disposal in the
backcountry.” Forest Service Research Note NE-246. Upper Darby, Pa.: USDA
Forest Service Northeastern Forest Experiment Station.
202—APPALACHIAN TRAIL CONFERENCE —BACKCOUNTRY SANITATION MANUAL
Jensen, M. E. 1984. “National Park Service remote area toilet facilities: experiences
and observations 1983 and 1984.” NPS Report No. 85-01-NPS/ESSD. Washington, D.C.: Environmental Sanitation Program, National Park Service.
Lachapelle, P. R., Land, B., & Clark, J. C. 1997. “The problem of human waste
disposal in national parks: a solar energy experiment in Yosemite National Park,
California.” USA Mountain Research and Development. 17(2):177-180.
Land, B. “Composting toilet systems: planning, design, and maintenance.” USFS
Technical Report No. SDTDC 9523-1803. San Dimas, Calif.: USDA Forest Service, Technology and Development Program, 1995.
Land, B. “Remote waste management.” USFS Technical Report No. SDTDC 95231202. San Dimas, Calif.: USDA Forest Service, Technology and Development
Program, 1995.
Leonard, R., & Fay, S. “Composting privy wastes at recreation sites.” Compost Science/Land Utilization, 1979. 20(1):36-39.
Leonard, R. E., & Plumley, H. J. “Human waste disposal in eastern backcountry.”
Journal of Forestry, 1979. 77(5):349–352.
Leonard, R. E., Spencer, E. L., & Plumley, H. J. Backcountry facilities: design and
maintenance. Boston, Mass.: Appalachian Mountain Club, 1981.
McDonald, J., Stanley, R., & McCauley, D. “Mount Whitney solar toilet.” USDA
Forest Service Engineering Field Notes, 1987. 19:13-19.
Mount Rainier National Park. Backcountry toilet technology workshop. Ashford, Wash.,
1993: USDI National Park Service, Mount Rainier National Park.
Temple, K., Camper, A., & Lucas, R. “Potential health hazards from human wastes
in wilderness.” Journal of Soil and Water Conservation, 1982. 37(6):357-359.
Voorhees, P., & Woodford, E. “NPS and the $300,000 privy: a parable for management.” The George Wright Forum, 1998. 15(1):63-67.
Weisberg, S. Composting options for wilderness management of human waste. Skagit
District: North Cascades National Park Service, 1988.
Wilderness Act of 1964. Pub. L. No. 88-577. 16 U.S.C. § 1131-1136.
Yosemite National Park. Backcountry human waste management: a guidance manual
for public composting toilet facilities. El Portal, Calif., 1994: USDI National Park
Service, Yosemite National Park.
Paul Lachapelle is a Research Assistant at the University of Montana. He can be reached
at School of Forestry SC 460 University of Montana Missoula, MT 59812; Tel: (406)
243-6657 Fax: (406) 243-6656 Email: <paullach@selway.umt.edu>
John C. Clark is Facility Management Specialist at Yosemite National Park. He can be
reached at El Portal, California 95318 USA Tel: (209) 379-1039 Fax: (209) 379-1037
E-mail: <John_C_Clark@nps.gov>
N
Examples of Regulatory
Correspondence
204—APPALACHIAN TRAIL CONFERENCE —BACKCOUNTRY SANITATION MANUAL
Figure N.1—Copy of the wastewater permit issued to the Green Mountain Club in 2000 for the installation of a beyond-thebin system at Butler Lodge on the Long Trail. This situation was a great example of how a state agency, unaware of composting
technology, learned about it when the Green Mountain Club provided a credible plan and specifications for the system. The
state subsequently approved the system. Letter from the Green Mountain Club.
APPENDIX N: EXAMPLES OF REGULATORY CORRESPONDENCE—205
206—APPALACHIAN TRAIL CONFERENCE —BACKCOUNTRY SANITATION MANUAL
Figure N.2—A copy of a letter written by the Appalachian Mountain Club’s Connecticut Chapter Trails Committee to State of
Connecticut’s Department of Public Health when seeking permission to install moldering privies on the A.T. in Connecticut.
This is an excellent example of one of the key steps in the process of seeking approval for the installation of a sanitation
management system on the A.T. Please keep in mind that in other states the process may require writing more than one
letter to the state, and may also include town and county health departments.” Letter from David Boone, Connecticut Chapter
Trails Committee of the Appalachian Mountain Club.
O
GMC Improves Sewage Management
Along Long Trail
From The Register, vol. 23, number 4 (Winter 1999).
By Pete Ketcham
During the 1999 field season, the Green Mountain Club (GMC) enhanced backcountry waste management at several sites on the northern portion of Vermont’s
Long Trail through several innovations in both technology and technique.
“Beyond the Bin” (BTB) liquid-separating composting toilets were built at both the
base of Camels Hump and at Taft Lodge, located just below the summit of Mt.
Mansfield, Vermont’s highest peak (4,395'). In addition, moldering privies were
constructed at Taylor Lodge, Jay Camp, Laura Woodward Shelter, and Shooting
Star Shelter. Those projects were made possible by an outpouring of dedicated volunteers and funding from the Vermont Department of Forests, Parks, and Recreation, the National Park Service, and the Appalachian Trail Conference.
Like many overnight sites along the Appalachian Trail (A.T.), local environmental
conditions on the Long Trail in northern Vermont present challenges to maintainers
trying to manage sewage. Those conditions include thin, poor soils, cold temperatures, high ambient air moisture, and heavy use. Conditions such as those, coupled
with a lack of field staff or volunteers, make dealing with sewage effectively nearly
impossible. The preferred method of dealing with sewage traditionally has been the
pit privy, which still represents the majority of waste-management systems on both
the Appalachian Trail and Long Trail. At most sites where the use is low to moderate throughout the season, a pit privy is still the best option. However, when use
increases, particularly at those sites with marginal environmental conditions, pit
privies fill up and become major headaches.
At many shelter sites, wastes decompose slowly simply because the pit extends well
below the biologically active layer of the forest floor (typically the first six inches)
or this layer does not exist at all. The waste that accumulates decomposes so slowly
that the rate of input from users exceeds the level of decomposition, and the pit
208—APPALACHIAN TRAIL CONFERENCE —BACKCOUNTRY SANITATION MANUAL
eventually will fill up. At many sites, there are no longer places to dig pits. Something must be done to provide adequate sanitation facilities or the future of these
overnight sites will be jeopardized. For clubs wishing to develop new overnight sites
and facilities, ATC direction requires that the proposed site be able to manage sewage in a way that protects the Trail experience for users, the health of visitors, and
the area’s resources. With public use on the rise, finding qualified sites is becoming
increasingly difficult.
Recently, moldering privies have emerged as a possible alternative for those challenging management situations. GMC, along with several other A.T.-maintaining
clubs, has been experimenting with them. Longtime GMC volunteer Dick Andrews
constructed the first prototype moldering (slow-composting) privy on the Long Trail/
Appalachian Trail in Vermont at Little Rock Pond Shelter in 1995. A moldering
privy utilizes the biologically active, upper six inches of the soil to better advantage
by doing away with a pit entirely. Instead, the waste pile sits in a wooden crib constructed on the surface of the soil (see photo). With the waste pile above the ground,
a variety of desirable common soil decomposers are attracted to it. Intense scavenging and competition created in the pile by these organisms helps destroy diseasecausing pathogens. The pile also receives a lot of aeration from air slats built in the
wood cribbing. This higher level of oxygen helps reduce odors. Liquid is allowed to
seep into the soil, where it is naturally treated by soil decomposers.
To further aid the decomposition process, field staff and maintainers introduce redwiggler worms, which have a voracious appetite for wastes of all kind. The worms
are particularly useful at colder, high-elevation sites with thin/ poor soils, where the
local population of soil decomposers is low. The worms are available from most
Figure O.1—The author
stands by a new moldering privy at Talor Lodge on
the lomg Trail. (Note twoby-fours for moving privy
onto the cribbing.
APPENDIX O: ARTICLE FROM ATC NEWSLETTER, THE REGISTER—209
garden-supply companies. Because the worms will not survive winter freezing, GMC
has been “growing” its own worm supply at GMC headquarters. The worms are
distributed to volunteers for introduction into toilets each spring.
The above-ground crib (4’ x 4’ x 30") is constructed using 6" x 6" timbers of either
pressure-treated or a rot-resistant wood, such as hemlock, stacked to create air slats
to promote thorough ventilation. Air slats are covered on both sides with 1/4" hardware cloth and fine-mesh fly screening that helps to keep the waste in and debris
and undesirable creatures out. Systems ranged in price from $90 to $400 per unit,
depending on whether the privy building needs replacing.
After two seasons of planning and fund-raising, “Beyond the Bin” (BTB) technology arrived at Taft Lodge on Mt. Mansfield and at the Monroe trailhead at Camels
Hump. The BTB was originally developed through a challenge cost-share grant to
the Appalachian Mountain Club (AMC) in 1995. AMC, along with former GMC
Field Assistant Paul Neubauer, constructed the first BTB along the AMC-maintained
portion of the A.T. in New Hampshire. Today, nearly all of AMC’s shelter sites
along the A.T. have BTB systems.
The BTB is a modification of the GMC’s batch-bin method of composting. The system
adds a perforated, stainless-steel straining plate in the outhouse waste catcher that allows all liquids to be gravity-separated away from the solids. Once separated, the liquid
then flows through a hose to a filter barrel (see photo). The 55-gallon barrel contains
layers of anthracite coal and washed septic stone. A biological community will develop
in the barrel that will consume pathogens and organic material in the liquid as it percolates through the barrel, before being discharged into the ground.
Figure O.2—The beyondthe-bin liquid filter barrel at
Taft Lodge. The barrel contains anthracite coal and
washed septic stone and
drains out from the bottom
into the soil, once filtered.
(Photo by Pete Ketcham)
210—APPALACHIAN TRAIL CONFERENCE —BACKCOUNTRY SANITATION MANUAL
The main advantage of that system is a drastic reduction in the amount of wood
chips needed for composting, which also significantly reduces the volume of sewage
that needs to be composted. In batchbin systems, excess liquid needs to be sopped
up with hardwood bark mulch or wood chips, which soaks up the moisture but expands the volume of the waste. This season, GMC caretakers composted approximately 630 gallons of sewage with the batch-bin system at Taft Lodge, due to the
presence of copious amounts of liquid. The BTB should reduce sewage volumes by
up to two-thirds annually. In addition, the drier sewage will compost at higher temperatures, producing a stable, pathogen-free end-product that can be safely spread
in the woods without threatening the area’s water quality.
After two months of operation, caretakers in the field reported a dramatic reduction
in the amount of sewage they have had to compost, as well as a decrease in odors
from their privies. During the 2000 field season, plans are to retrofit more privies to
moldering systems and to modify other existing batch-bin composters over to BTB
systems. A batch-bin system with a BTB filtering component will cost between
$800 and $1,500. The entire BTB system weighs about 600 pounds and requires
many volunteers, to transport to backcountry sites. The BTB is one of the more
effective waste-management systems that has been used on the A.T. in New England. The cost is higher than a moldering privy, and it does require frequent maintenance and tending, so it may not be appropriate for some clubs or organizations
with smaller budgets or labor forces. Funding for the BTB projects was made possible through generous grants from the Vermont Department of Forests, Parks, and
Recreation, the Burlington Section of GMC, and Concept II (a local business) from
Morrisville, Vt.
GMC is using the knowledge gained to develop a moldering-privy manual, which
will be available in February. Thanks to an NPS challenge cost-share, a backcountry
sanitation manual for Trail maintainers will be completed by 2001.
Pete Ketcham is a regional field supervisor for the Green Mountain Club. He also
has worked with the Appalachian Mountain Club and Randolph Mountain Club in
New Hampshire as a backcountry hut naturalist and facility caretaker.
A version of this article was printed in the Spring 1999 issue of the Long Trail
News, GMC’s quarterly newsletter.
For more information on backcountry waste management, contact Pete Ketcham at
the Green Mountain Club; 4711 Waterbury-Stowe Road, Waterbury Center, Vermont 05677; (802) 244-7037 ext. 17; or <Pete@~greenmountainclub.org>.
P
Owner-Built Continuous Composters
Figure P.1—This is an example of plans for the construction of an owner-built, continuous composting system. The plans pictured are for a Clivus Minimus, which is modeled after the Clivus Multrum. The Pennsylvania Composter, a unit in use on the A.T. in
Pennsylvania, Maryland, and New Jersey, is a similar design. Diagram from the Center for Low-Cost Housing of McGill University and The Composting Toilet System Book
by David Del Porto and Carol Steinfeld.
212—APPALACHIAN TRAIL CONFERENCE —BACKCOUNTRY SANITATION MANUAL
Figure P.2—A diagram of the Mountain Club of Maryland’s “Pennsylvania Composter.” This system is also referred to as a
“Clivus Minimus,” because it is an owner-built version of the Clivus system. For plans and additional information, contact the
Mountain Club of Maryland’s Ted Sanderson (Contact information is in the Contact List in this Appendix).” Diagram from Ted
Sanderson and the Mountain Club of Maryland.
Q
Plans for a Wooden Packboard
Figure P.3—Plans for construction of the Appalachian Mountain Club’s wooden
packboard. This packboard has been found to be the best for transporting composting
toilet system components into the field as well as bark mulch or other bulking agents
by the Green Mountain Club and Appalachian Mountain Club.
Index
A
access hatch 41
accessibility 41
acidity
effect on systems 16
actinomycetes 26, 31, 80,
82, 104, 134
in compost 27
action plan 86
aeration 104
aerobic 134
aerobic composting toilets 19
aerobic conditions 22, 79
aerobic decomposition 18, 22,
29, 65
aerobic treatment 7
aesthetic quality
protection of 18, 35
aesthetics 6, 61, 100
Agency of Natural Resources, Vt. 39
airlift 77, 90, 112
cost of 77, 90, 103
algal blooms 128
AMC. See Appalachian Mountain
Club (AMC)
Americans with Disabilities Act of
1990 41
ammonia 80, 92, 109
and odor 25
amoebas 30
anaerobic conditions 22, 54, 105,
134
anaerobic decomposition 18, 23, 92
angle brackets 58
animals
and buried wastes 20
anthracite coal
in leach fields 114
antibiosis 65
antibiotics 26, 31
Appalachian Mountain Club (AMC)
16, 39, 47, 63, 112, 132, 146
Appalachian National Scenic Trail
39
Appalachian Trail 15
Appalachian Trail Conference
(ATC) 5, 16, 17, 37,
39, 46, 68, 145
Appalachian Trail Park Office
(ATPO) 147
approval process 38
Architectural and Transportation
Barriers Compliance Act of 1968
41
Ascaris (roundworm) 29
Ascaris eggs
survival in compost 29
ash 50, 115
ATC. See Appalachian Trail Conference (ATC)
ATVs 76
B
backcountry
moldering privy in 46
backcountry facilities
location of 15
Backcountry Research Project. See
USDA Forest Service: Backcountry Research Project
backcountry sanitation literature 189
backcountry sanitation management
history of 15
Backcountry Sanitation Manual 5
backcountry systems
relative effectiveness of 8
bacteria 26, 65, 104, 134
aerobic 23, 26
and composting 22, 26
anaerobic 23
pathogenic 30
thermophilic 24
bacterial decomposition 113
bacterial growth 80
Bacterioides 27
bark 25, 26, 33, 64, 65,
87, 89, 91, 106
amounts required 74, 75
as bulking agent 23, 25
dryness of 93
sources for 64
storage of 73
bark consumption 90
bark mulch 72, 99
transporting 90
barrel toilets 38
barrels
for airlift 112
batch-bin 134
batch-bin composting 63–88
compared to moldering privy 47
system operator for 66
batch-bin composting system 16, 19,
23, 30, 46
converting to beyond-the-bin
system 93
cost of 53
development of 16
diagram of 65
in Green Mountains 63
speed of composting 31
themophilic 103
in White Mountains 63
bathing 21
Bdellovibrio bacteriovorus 26
bears
and food waste 20
beetles 27, 104
beyond-the-bin liquid separation 63
beyond-the-bin (BTB) systems
23, 30, 78, 90–95, 105, 108,
134
cost of 93
diagram of 91
installation of 94
speed of composting 31
visual impact of 93
winterizing 93
bibliography 159
bins
construction of 70
Bio-Sun 31, 104, 108
beyond-the-bin system 105
maintenance of 106
Bio-Sun Systems, Inc. 104
Bio-Sun WRS 1000 104
biological treatment 7
biologically active 134
black water 109
blackflies 79
bleach 32
blisters 33
Board of Managers, ATC 36
bootleg trails 18
bottles 21
broom 67
bulking agent 25, 50, 54, 62, 73,
99, 109, 111, 134
in moldering privy 50
insufficient 28
quantities required 51
transporting 76
burial 103
shallow 18
Butler Lodge 39
C
C:N ratio 80, 91. See also
carbon:nitrogen ratio (C:N)
high 25
low 25
optimum 25
testing 25
cans 21
capacity
batch-bin 77
Cape Cod, Mass. 8
carbon 25, 80, 104
carbon dioxide 25, 80, 109
carbon:nitrogen ratio (C:N) 25, 73
caretakers 18, 53, 99, 102-103, 107,
114
carpentry 93
Carter Notch Hut 101, 132
case studies 97, 98–115
catcher 64, 67
cleaning 68
emptying 85
housing for 66
in winter 88
materials for 67
categorical exclusion 38
catholes 5, 6, 18, 19, 37, 46
effective use of 19
high elevation 19
preparation of 19
cedar landscaping lumber 98
Center for Ecological Pollution
Prevention (CEPP) 148
cesspools 51, 112
chain saw 60
charcoal 33, 129
chemical toilets 6
chlorinator 114
chlorine 132
chum toilet 18, 135
circular saw 60
Class A sludge 41
Clean Water Act 38
cleaning 102
cleaning supplies 67
cleanout door 109
Clivus Multrum 9, 31, 101–
102, 108
capacity of 108
cost of 108
design of 16, 101, 109
insulation of 108
unsuitability for backcountry use
108
clothing 32
clubs 6
Trail-maintaining 36
codes
applicability of 6
colder months
increasing use during 106
collembolas (springtails) 27
competition
microbial 31
compliance 36
compost
burial of 50, 106
contamination of 79
disposal of 41, 111
drying 94
dryness of 92
mixing 100
recycling 50
spreading 82
stability 82
turning 23, 51, 72
compost bin 64, 70
fullness of 85
compost pile
mixing 104
compost run 65, 79, 82
temperature profile of 80
compost season 77
composting 6, 18, 22, 135
cool (moldering) 48
health and safety issues 6
in moldering privy 100
composting chambers
waterproof 39
composting systems 5
history of 5
composting toilet 28
Composting Toilet System Book, The
10
composting toilet systems
number of 16
composting toilets 19, 38, 39
at AMC huts 132
site limitations 19
composting tools 72–73, 87
Comprehensive Plan for the Appalachian
Trail 36
Comprehensive Plan for the Management of the Appalachian Trail 40
concrete reinforcing bar (rebar) 59
cone 68
confined spaces 41
contact list 149
containers
construction of 93
effect on temperature 25
containment bin 108
continuous composters
owner-built 211
continuous-composting systems
24, 31, 46, 53, 101–103, 105,
135
cost of 55
maintenance of 102
cooperative management 38
costs
of Bio-Sun units 104
of continuous-composting toilets
101
Crag Camp 103, 104, 105, 108
crib 48, 54
construction of 48
cuts 33
cysts 30
D
day use 106
decomposition
in winter 87
primary 31
secondary 31
decomposition and composting
process 22
dehydration toilets 19, 103
Department of Forests, Parks, and
Recreation, Vt. 39, 46
Department of Public Health, Conn.
39
design approval 41
destruction of pathogens 25
disabilities
accessibility issues 41
disease
and sewage 18
dish washing 21, 129
dispersed disposal 17
dog waste 20
door handles 58
doser 114, 132
drainage
for washpits 130
drill 60, 62
drill bits 58
drinking water 21
drying rack 27, 31, 63, 65, 71, 105
plans for 186
space available on 86
drying screens 94
duff 26, 48, 72, 73, 98
E
E. coli 26, 27, 29
effluent
environment regulations for 95
septic tank 7
testing 94
Eisenia foetida (redworm) 52
electric fences 69
elevation change 94
encapsulation
pathogen 23, 135
Entomoeba histolyticia 29
environment
protection of 5
environmental assessment 38
environmental impact statement 38
environmental impacts 17
Environmental Protection Agency
(EPA) 38
sludge regulations 41
enzymes 26
EPA. See Environmental Protection
Agency (EPA)
eutrophication 129
evaporator toilets 38
exhaust 105
exhaust stack 108
exotic species 53
experimental systems 47
F
face shields 33
fan 110
fecal waste 18
feces
C:N ratio of 91
separation from urine 28
federal land
waste policies for 19
feminine hygiene products 20
fertilizer 111
field assembly 61
field office
ATC regional 6
finished compost 65, 82
fire
danger of 102
fire pit 129
fire wastes 18, 21
fires
prohibitions on 20
fishing lines and hooks 21
flashing 58, 62
flies
in Clivus Multrum toilets 110
flooding 7
floor
privy 67
flush toilet 48
flush toilets 7, 38, 112
fly eggs 110
foil 21
food scraps
C:N ratio of 25
in moldering privy 52
food wastes 6, 18, 20, 109
at trailheads 21
burning 20
burying 20
putrefaction of 20
rinsing 20
Forest Master Plan 17
Forest Service, USDA. See USDA
Forest Service
freezing 86
frontcountry 101
moldering privy in 46
frozen waste 106
fungi 26, 31, 65, 80, 104, 135
in compost 27
G
Galehead Hut 101
garbage 106
garbage dumping 6
Giardia lamblia 20, 29
glossary 134
gloves 32, 33
GMC. See Green Mountain Club
(GMC)
gowns
rubber 33
graffiti
discouraging 67
Grants-to-Clubs
ATC 104
gravity-fed systems 94
Gray Knob 103, 104, 105, 107
gray water 6
aesthetics of 128
and plants 130
at AMC huts 132
defined 128
management of 128–129
safety precautions in handling 128
gray water chutes
maintenance of 131-132
grease 131-132
Great Smoky Mountains National
Park 39, 68
Green Mountain Club 57
Green Mountain Club (GMC)
5, 16, 17, 39, 46, 63, 146
Green Mountains, Vt. 16, 46, 63
Greenleaf Hut 112
ground water 28, 54, 129
H
hacksaw 60
hammer 62
hand sanitizer
waterless 32
hand-washing 21, 129
hardware cloth 48
replacing 56
haul-out systems 112
hay 51
head room 41
health and safety issues 6,29
helicopters 15, 20, 40,
77, 90, 103, 132
hepatitis 29
high water tables 54
high-use campsites 37
high-use sites 16, 82, 102
washpits at 129
high-use situations 99
hiker behavior 61
hikers
protection of 5
response from 99
hookworm 29
Hugo, Victor 2
human waste
incineration of 115
volume of 15
Humanure Handbook: A Guide to
Composting Human Manure 10
humic acids 80
humus 65
gathering 94
huts, AMC 101, 132
hydrogen peroxide 32
hygienic wastes 21
I
ice
accumulation of 110
illegal tenting areas 130
illness 31
incineration 115
incineration toilets 6, 38, 19
incinerator
odor from 115
prototype 115
wood-fired 115
incinerators
cost of 115
infection 31, 33
insect bites
sanitary issues 32
insect screening 98
insects 20, 48, 68, 101
installations 6
instructional signs 131
invertebrates 104, 110
mesophilic 24
native 48
isopods 27
J
Jenkins Publishing 148
K
LMP. See local management plan
(LMP)
local laws 38
local management plan (LMP) 17,
36
local management planning 6, 36
Local Management Planning Guide
17, 36, 37
Log Cabin, The 103, 107
Lonesome Lake Hut 101
Long Trail 15
sewage management along 207
Long Trail System 17
low-flow toilets 113
low-use sites 78
low-use systems 28
Klebsiella 27
L
labor 90
for sanitation projects 5
paid 5
volunteer 5
Lactobacillus 27
ladder 41
Lakes of the Clouds Hut 112
land managing agencies 5, 6
landscaping timbers 57
leach field
septic 7, 112, 132
leachate 27, 135
leaching 18
leakage
in winter 88
Leave No Trace 20, 21, 129
leaves 26, 51, 72, 73
Les Miserables 2
level 62
lid
securing 87
lime
and compost 25
Lindstrom, R.E. 16
liquid
reduction of 91
liquid accumulation 105, 111
liquid effluent 101
liquid evaporation
in Clivus Multrum 109
liquid separation 90
liquids
drainage of 23
litter 18, 20
Little Rock Pond 46
Little Rock Pond Shelter 9, 55
experimental privy at 98
M
Madison Spring Hut 112
maintaining clubs 18
maintenance 77
management plans
local 6
mank layer 78-79, 93
Manual For Bin Composting 9
manure worms 48. See also redworms
maps 130
marshy areas 83
materials
sources for 172
mechanical counter 107
Memorandum of Understanding 36
mercaptans 27
mesophilic 135
mesophilic composting 24, 30, 103
methane 67, 109
explosive dangers of 51
microbial activity 23
effect of nutrients on 25
microorganisms 22, 65, 104
aerobic 27
native 48
millipedes 27, 104
miter saw 60
mites 27, 104
mixing 79
Mizpah Spring Hut 101
moisture
and composting 22
moisture content 23
ideal for composting 23
moisture level 79
moldering 108
process of 48
moldering crib 27
construction of 57, 61
moldering privy 5, 19, 31, 39, 46–
62, 98–100, 135
capacity 46, 50
compared 46
convenience of 54
cost of 55
diagram of 49
double-chambered 47
maintenance requirements 54, 100
moving 54
plans for 181
siting of 54, 61
user responsibility 100
Moldering Privy Manual and Design 47
molds 26
money
for sanitation projects 5
mosquitoes 79
Mt. Mansfield 39
mulch
expense of transporting 90
mule train
removal by 20
municipal waste water 6
N
National Environmental Policy Act
of 1969 (NEPA) 38
National Park Service (NPS)
38, 39, 46
National Scenic Trails System Act
40
needles
conifer 51
NEPA. See National Environmental
Policy Act of 1969 (NEPA)
nitrogen 25, 80
noise
from ventilation turbine 110
non-sewage waste 20
nonorganic contaminated trash
18, 20
notification 39
nuisance animals 20
nutrient elements 7, 25, 31
nutrient loading 20
O
obligate anaerobes 31
Occupational Safety and Health
Administration (OSHA) 41
odor
22, 23, 27, 28, 55, 68, 92, 99, 100,
102, 105, 106, 108, 109
effect of sun 24
on-site management 20
operator 66, 80
organic matter
added to pit toilets 19
organisms
types of in composting toilet 26
OSHA. See Occupational Safety and
Health Administration (OSHA)
outhouse 48
aesthetics 67
batch-bin 66
construction of 57
outhouse door 88
outhouse plans 174
overnight fees 104
overnight sites 38
overnight-use areas 17
oxidation 65
oxygen 80
and composting 22
P
pack stock 6
packboard 76
plans for 213
pamphlets
instructional 21
paper 21
parasites 29, 135
parasitic worms 29
Park Master Plan 17
Park Service. See National Park
Service
particle size 31
pathogen 135
pathogen destruction 22, 65
pathogen survival 23, 83
pathogens 7, 18, 29, 106
elimination of
in Clivus Multrum toilets 109
in gray water 128
long-term viability of 19, 30
testing for 107
peak nights 94
peat moss 26, 51, 73, 111
Pennsylvania Game Commission 39
Perch, The 103, 104, 105, 108
percolation 7
perforated pipe 114
permafrost 101, 112
permits 6
pet wastes 6, 18
pH 135
pH range 25
optimum for compost 25
phosphorus 25
pilot holes 59
pit latrines
temporary 19
pit privies 5, 15, 18, 28, 38,
98, 136
pit toilets 6, 18, 28, 46, 103, 112
food waste in 20
inadequacy of 16
location near water 15
modifications of 18
pollution from 28
pits
digging out 18
planning guide 36
plastic 21
plastic sheeting 75
plumbing 93
policies 40
policy
ATC 6
lack of standard 37
polio 29
pollution 7, 17
at overnight sites 129
ponds 83
mountain 15
porcupines 70
potassium 25
premature composting 80
pressure-treated (PT) wood 58
toxicity of 58
primitive experience 76
primitive recreation
popularity of 15
privacy 61
for urination 92
privies
anaerobic 51
batch-bin 6
construction 59–60
moldering 5, 6
pit 5
placement of 18
siting across watercourse 21
privy bench 67
privy shelter 18
problems
backcountry waste 5
project leader 85
propane-fired systems 103
proposal
submitting 38
protozoa 29, 136
public health 54
public health service 38
pump 111
Q
quantities 81
R
rake 73
Randolph Mountain Club (RMC)
102, 107, 147
rebar
cutting 60
record forms 84
record keeping 6
record-keeping 84–85
redworms
24, 26, 39, 48, 51, 62, 100,
111
benefits of 53
information on 52
predators of 56
propagation of 56, 99
sources for 55
survival of 51
regional management committee
mid-Atlantic 37
regulations
state and local 38
regulatory correspondence 203
regulatory issues 35
regulatory process 6, 37
Rehabilitation Act of 1973 41
removal of wastes
cost of 20
report 85
research natural areas 41
residential waste water 6
resource damage
prevention of 18
ridgerunners 18
RMC 104, 107. See Randolph
Mountain Club (RMC)
road access 76
roadless areas 41
rodents 48, 50
roofing 58
S
safety 99
safety equipment 32, 33
Salmonella 29
sanitary landfill 106
sanitary practices 88
sanitation
managing
importance of 6
on A.T.
history of 6
sanitation codes 6, 7
sanitation management
benefits of 17
sanitation systems
aesthetics of 6
sawdust 51, 73
as bulking agent 25
scattering 20
screen 71, 130
screening 48, 58, 62
secondary pits 130
septage 136
septic field 114
septic systems 7
septic tank 111, 113
function of 7
pumping 7
reliability of 7
sewage 18, 31
C:N ratio of 25
mixing 93
on clothes 33
safety of 31
sewage systems
household 7
sewage treatment plants 7, 112
shaving 21
shavings 51, 104, 111
weight of 99
sheeting
plastic 72
shelter 48
Shenandoah National Park 37
shovel 33, 62, 72
long-handled 73
shrews 51
sifting 72
sifting screen 63, 72
sign 130
signs 92, 130
examples of 162
stewardship 21, 58
sled 76
sledge 62
slope
of compost pile 112
steepness of 98
slugs 27
smell 18
snow
clearing 50
snow holes 19, 88
snow loads 70
snowmobiles 76
soap 21, 131
antibacterial 32
bar 32
dish washing 32
softwood shavings 99
soil
composition 47
effect on systems 16
soil animals 27
soil characteristics 18
soil compaction 130
soil quality
ridgelines 15
soils
porous 22
shallow 19
solar gain
effect on ventilation 24
solar hot box 198
solar panel 71, 104, 108
solar power 102, 105
solids
dispersal of in septic systems 7
in septic tank 114
specially designated areas 41
speed square 60
spikes 58
splash guard 62
spreading schedule 86
spring action plan 86
spring and fall operations 6
springtails 104
stairs 41, 62
standards 7
staple gun 62
staples 58
state laws 38
state regulations 106
stewardship signs
examples of 162
storage capacity 71
storage containers 69
fullness of 86
in winter 88
protecting 69
stored waste 80
strainer
placement of 92
Stratton Pond 27
straw 51
streams 83
Streptomyces 27
substrate 136
substrate particles
size of 23
sun
effect on composting 24
sun and shade 61
systems
commerical 6
descriptions of 45
T
talus 98
tanks
septic 7
tape measure 62
temperatures 30, 104, 109
after composting 82
and composting 22, 24
and moldering privy 48
and pathogen destruction 30
of moldering privy waste 48
mesophilic 24
thermophilic 24
temperature range 22
thermometer 75, 81, 104
thermophilic 136
thermophilic composting
24, 30, 48, 53, 103
thermophilic conditions 82
timber
sawing 94
timberline 101
timbers
length of 98
time
and composting 22, 31
tin snips 60
toilet bench
construction of 51
toilet facilities
winter 19
toilet paper 20
toilet seats 58
toiletry 129
toilets
approved types 38
tools 33, 51, 59, 60
contamination of 72
storage of 72
toothbrushing 21
topography 61
Trail clubs 5
trail maintainers
protection of 5
trailheads
trash at 21
training
requirements 103
transport containers 72
trash 18, 20
from hikers 89
in moldering privy 51
unsorted 21
trees
cutting for fires 21
troubleshooting 137
truck
removal by 20
turning fork 33, 73
turning the compost pile 24, 79, 82
Typhoid 29
U
University of Vermont 39
urinals 28
urination
at overnight sites 20
urine 18, 20, 27, 78
C:N ratio of 25, 92
in aerobic systems 20
in anaerobic systems 20
in moldering privy 50
odor of 20
separation from feces 28, 50
sterility of 27
urine diversion
in moldering privies 100
urine diversion device 74
usage
problems estimating 107
USDA Forest Service 37
Backcountry Research Project 16
V
vault toilets 6, 39, 136
vegetation
damage to 18
vent 99, 102
vent stack 51, 66, 110
ventilation 110
Venturi effect 108
viruses 29
visitors
volume of 94
visual impact 90
voids
in compost 23
volume
and insulation 31
of compost 102
volunteers
and mulch transport 76
W
wash jug 32
wash station 76
wash water 6, 129
wash water sites
maintenance of 131
permits for 131
washing area
location of 129
washpits 21
clogged 131
construction of 21, 130
diagram of 188
maintenance of 21
siting of 21, 129
waste
per person 27
transporting 68
wastes
mixing of 64
water
contamination by pit privies and
catholes 18, 21
distance from 95
pollution from food waste 20
water pollution 54
water quality
protection of 18
water sources 61, 83
water supplies 17
water table 20, 61, 136
high 19
waterborne pathogens 20
watershed 136
weather
covering drying compost because of
94
effect on systems 16
White Mountains, N.H.
16, 63, 101, 112
Wilderness Act of 1964 40
wilderness areas
federally designated 40, 90
construction in 40
use of motorized equipment in
40
wildlife entanglement 21
wind
effect on composting 24
effect on temperature 25
winds
prevailing 61
winter
batch composting in 87–88
equipment and clothes for 88
winter access 67
winter storage 87
winter use 87–89
wood
charred 21
untreated 58
wood chips 51
wood shavings 26
worms 27
red wigglers See redworms
Y
"yellow snow" 20
Z
Zealand Falls Hut 112, 132